CWE-444
AllowedInconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling')
Abstraction: Base · Status: Incomplete
The product acts as an intermediary HTTP agent (such as a proxy or firewall) in the data flow between two entities such as a client and server, but it does not interpret malformed HTTP requests or responses in ways that are consistent with how the messages will be processed by those entities that are at the ultimate destination.
674 vulnerabilities reference this CWE, most recent first.
GHSA-9298-4CF8-G4WJ
Vulnerability from github – Published: 2024-10-29 14:45 – Updated: 2025-01-21 17:53Impact
A remote client may send a request that is exactly recv_bytes (defaults to 8192) long, followed by a secondary request using HTTP pipelining.
When request lookahead is disabled (default) we won't read any more requests, and when the first request fails due to a parsing error, we simply close the connection.
However when request lookahead is enabled, it is possible to process and receive the first request, start sending the error message back to the client while we read the next request and queue it. This will allow the secondary request to be serviced by the worker thread while the connection should be closed.
Patches
Waitress 3.0.1 fixes the race condition.
Workarounds
Disable channel_request_lookahead, this is set to 0 by default disabling this feature. For this vulnerability this value is required to be changed from the default.
For more information
If you have any questions or comments about this advisory: * Open an issue in https://github.com/Pylons/waitress/issues (if not sensitive or security related) * email the Pylons Security mailing list: pylons-project-security@googlegroups.com (if security related)
Thanks
- m4yfly and urn1ce From TianGong Team of Legendsec at Qi'anxin Group.
{
"affected": [
{
"package": {
"ecosystem": "PyPI",
"name": "waitress"
},
"ranges": [
{
"events": [
{
"introduced": "2.0.0"
},
{
"fixed": "3.0.1"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [
"CVE-2024-49768"
],
"database_specific": {
"cwe_ids": [
"CWE-367",
"CWE-444"
],
"github_reviewed": true,
"github_reviewed_at": "2024-10-29T14:45:03Z",
"nvd_published_at": "2024-10-29T15:15:11Z",
"severity": "CRITICAL"
},
"details": "### Impact\n\nA remote client may send a request that is exactly `recv_bytes` (defaults to 8192) long, followed by a secondary request using HTTP pipelining.\n\nWhen request lookahead is disabled (default) we won\u0027t read any more requests, and when the first request fails due to a parsing error, we simply close the connection.\n\nHowever when request lookahead is enabled, it is possible to process and receive the first request, start sending the error message back to the client while we read the next request and queue it. This will allow the secondary request to be serviced by the worker thread while the connection should be closed.\n\n### Patches\n\nWaitress 3.0.1 fixes the race condition.\n\n### Workarounds\n\nDisable `channel_request_lookahead`, this is set to `0` by default disabling this feature. For this vulnerability this value is required to be changed from the default.\n\n### For more information\n\nIf you have any questions or comments about this advisory:\n* Open an issue in https://github.com/Pylons/waitress/issues (if not sensitive or security related)\n* email the Pylons Security mailing list: [pylons-project-security@googlegroups.com](mailto:pylons-project-security@googlegroups.com) (if security related)\n\n### Thanks\n\n- m4yfly and urn1ce From TianGong Team of Legendsec at Qi\u0027anxin Group.",
"id": "GHSA-9298-4cf8-g4wj",
"modified": "2025-01-21T17:53:26Z",
"published": "2024-10-29T14:45:03Z",
"references": [
{
"type": "WEB",
"url": "https://github.com/Pylons/waitress/security/advisories/GHSA-9298-4cf8-g4wj"
},
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2024-49768"
},
{
"type": "WEB",
"url": "https://github.com/Pylons/waitress/commit/e4359018537af376cf24bd13616d861e2fb76f65"
},
{
"type": "PACKAGE",
"url": "https://github.com/Pylons/waitress"
},
{
"type": "WEB",
"url": "https://github.com/pypa/advisory-database/tree/main/vulns/waitress/PYSEC-2024-210.yaml"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N",
"type": "CVSS_V3"
},
{
"score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N",
"type": "CVSS_V4"
}
],
"summary": "Waitress has request processing race condition in HTTP pipelining with invalid first request"
}
GHSA-92GR-8FH9-J8VQ
Vulnerability from github – Published: 2022-05-14 01:04 – Updated: 2022-05-14 01:04The net/http library in net/textproto/reader.go in Go before 1.4.3 does not properly parse HTTP header keys, which allows remote attackers to conduct HTTP request smuggling attacks via a space instead of a hyphen, as demonstrated by "Content Length" instead of "Content-Length."
{
"affected": [],
"aliases": [
"CVE-2015-5739"
],
"database_specific": {
"cwe_ids": [
"CWE-444"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2017-10-18T20:29:00Z",
"severity": "CRITICAL"
},
"details": "The net/http library in net/textproto/reader.go in Go before 1.4.3 does not properly parse HTTP header keys, which allows remote attackers to conduct HTTP request smuggling attacks via a space instead of a hyphen, as demonstrated by \"Content Length\" instead of \"Content-Length.\"",
"id": "GHSA-92gr-8fh9-j8vq",
"modified": "2022-05-14T01:04:20Z",
"published": "2022-05-14T01:04:20Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2015-5739"
},
{
"type": "WEB",
"url": "https://github.com/golang/go/commit/117ddcb83d7f42d6aa72241240af99ded81118e9"
},
{
"type": "WEB",
"url": "https://bugzilla.redhat.com/show_bug.cgi?id=1250352"
},
{
"type": "WEB",
"url": "http://lists.fedoraproject.org/pipermail/package-announce/2015-October/167997.html"
},
{
"type": "WEB",
"url": "http://lists.fedoraproject.org/pipermail/package-announce/2015-October/168029.html"
},
{
"type": "WEB",
"url": "http://rhn.redhat.com/errata/RHSA-2016-1538.html"
},
{
"type": "WEB",
"url": "http://seclists.org/oss-sec/2015/q3/237"
},
{
"type": "WEB",
"url": "http://seclists.org/oss-sec/2015/q3/292"
},
{
"type": "WEB",
"url": "http://seclists.org/oss-sec/2015/q3/294"
},
{
"type": "WEB",
"url": "http://www.securityfocus.com/bid/76281"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
"type": "CVSS_V3"
}
]
}
GHSA-92X4-7936-WW96
Vulnerability from github – Published: 2026-07-08 18:31 – Updated: 2026-07-10 18:32OpenVPN Access Server 2.7.2 through 3.1.0 accepts bare line-feed sequences inside HTTP header values, allowing remote attackers to perform HTTP request smuggling when deployed behind a reverse proxy
{
"affected": [],
"aliases": [
"CVE-2025-3110"
],
"database_specific": {
"cwe_ids": [
"CWE-444"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2026-07-08T17:17:19Z",
"severity": "MODERATE"
},
"details": "OpenVPN Access Server 2.7.2 through 3.1.0 accepts bare line-feed sequences inside HTTP header values, allowing remote attackers to perform HTTP request smuggling when deployed behind a reverse proxy",
"id": "GHSA-92x4-7936-ww96",
"modified": "2026-07-10T18:32:04Z",
"published": "2026-07-08T18:31:36Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2025-3110"
},
{
"type": "WEB",
"url": "https://openvpn.net/as-docs/as-3-2-release-notes.html"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N",
"type": "CVSS_V3"
},
{
"score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:L/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X",
"type": "CVSS_V4"
}
]
}
GHSA-93C7-7XQW-W357
Vulnerability from github – Published: 2025-06-20 18:07 – Updated: 2025-06-20 18:07A request smuggling vulnerability identified within Pingora’s proxying framework, pingora-proxy, allows malicious HTTP requests to be injected via manipulated request bodies on cache HITs, leading to unauthorized request execution and potential cache poisoning.
Fixed in
https://github.com/cloudflare/pingora/commit/fda3317ec822678564d641e7cf1c9b77ee3759ff
Impact
The issue could lead to request smuggling in cases where Pingora’s proxying framework, pingora-proxy, is used for caching allowing an attacker to manipulate headers and URLs in subsequent requests made on the same HTTP/1.1 connection.
{
"affected": [
{
"package": {
"ecosystem": "crates.io",
"name": "pingora-core"
},
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"fixed": "0.5.0"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [
"CVE-2025-4366"
],
"database_specific": {
"cwe_ids": [
"CWE-444"
],
"github_reviewed": true,
"github_reviewed_at": "2025-06-20T18:07:47Z",
"nvd_published_at": null,
"severity": "HIGH"
},
"details": "A request smuggling vulnerability identified within Pingora\u2019s proxying framework, pingora-proxy, allows malicious HTTP requests to be injected via manipulated request bodies on cache HITs, leading to unauthorized request execution and potential cache poisoning.\n\n### Fixed in\nhttps://github.com/cloudflare/pingora/commit/fda3317ec822678564d641e7cf1c9b77ee3759ff \n\n### Impact\nThe issue could lead to request smuggling in cases where Pingora\u2019s proxying framework, pingora-proxy, is used for caching allowing an attacker to manipulate headers and URLs in subsequent requests made on the same HTTP/1.1 connection.",
"id": "GHSA-93c7-7xqw-w357",
"modified": "2025-06-20T18:07:47Z",
"published": "2025-06-20T18:07:47Z",
"references": [
{
"type": "WEB",
"url": "https://github.com/cloudflare/pingora/security/advisories/GHSA-93c7-7xqw-w357"
},
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2025-4366"
},
{
"type": "WEB",
"url": "https://github.com/cloudflare/pingora/commit/fda3317ec822678564d641e7cf1c9b77ee3759ff"
},
{
"type": "WEB",
"url": "https://blog.cloudflare.com/resolving-a-request-smuggling-vulnerability-in-pingora"
},
{
"type": "PACKAGE",
"url": "https://github.com/cloudflare/pingora"
},
{
"type": "WEB",
"url": "https://rustsec.org/advisories/RUSTSEC-2025-0037.html"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:A/VC:H/VI:H/VA:N/SC:L/SI:L/SA:N",
"type": "CVSS_V4"
}
],
"summary": "Pingora has a Request Smuggling Vulnerability"
}
GHSA-94F4-HR76-P5J6
Vulnerability from github – Published: 2026-06-16 17:36 – Updated: 2026-09-01 15:30Summary
A vulnerability in ASGI web servers and starlette's trust on those web servers enables an authentication bypass of the OpenAI API AuthenticationMiddleware, which was discovered during @x41sec's source code audit.
It allows to use the API without providing the configured VLLM_API_KEY or --api-key.
Details
In https://github.com/vllm-project/vllm/blob/v0.14.0/vllm/entrypoints/openai/api_server.py#L689-L692 the url_path is taken from the URL, which is reconstructed by starlette based on the request scope.
from starlette.datastructures import URL, Headers, MutableHeaders, State
# ...
url_path = URL(scope=scope).path.removeprefix(root_path)
headers = Headers(scope=scope)
if url_path.startswith("/v1") and not self.verify_token(headers):
response = JSONResponse(content={"error": "Unauthorized"}, status_code=401)
return response(scope, receive, send)
return self.app(scope, receive, send)
The request scope includes the request's Host: header and reconstructs the URL as shown below:
f"{scheme}://{host_header}{path}"
Neither starlette nor any of the ASGI servers (including uvicorn, which vllm uses) properly filter the Host: header for invalid characters. This allows an attacker to include special URL characters such as / or ? in the Host: header and thereby control the reconstructed URL and it's .path attribute.
FastAPI/starlette's routing uses the HTTP path and does not depend on the parsed url.path attribute, allowing attackers to reach an endpoint via a certain path while providing a different value in the .path.
Impact
- Instances of vllm that use an API Key for the OpenAI API and expose the API to attackers.
- Instances behind an RFC-conforming web server (such as nginx) are not affected.
{
"affected": [
{
"package": {
"ecosystem": "PyPI",
"name": "vllm"
},
"ranges": [
{
"events": [
{
"introduced": "0.3.0"
},
{
"fixed": "0.22.0"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [
"CVE-2026-48746"
],
"database_specific": {
"cwe_ids": [
"CWE-444",
"CWE-501"
],
"github_reviewed": true,
"github_reviewed_at": "2026-06-16T17:36:41Z",
"nvd_published_at": "2026-06-22T23:16:30Z",
"severity": "CRITICAL"
},
"details": "### Summary\n\nA vulnerability in ASGI web servers and starlette\u0027s trust on those web servers enables an authentication bypass of the OpenAI API `AuthenticationMiddleware`, which was discovered during @x41sec\u0027s source code audit.\nIt allows to use the API without providing the configured `VLLM_API_KEY` or `--api-key`.\n\n### Details\n\nIn https://github.com/vllm-project/vllm/blob/v0.14.0/vllm/entrypoints/openai/api_server.py#L689-L692 the `url_path` is taken from the `URL`, which is reconstructed by _starlette_ based on the request `scope`.\n\n```py\nfrom starlette.datastructures import URL, Headers, MutableHeaders, State\n\n# ...\n\nurl_path = URL(scope=scope).path.removeprefix(root_path)\nheaders = Headers(scope=scope)\nif url_path.startswith(\"/v1\") and not self.verify_token(headers):\n response = JSONResponse(content={\"error\": \"Unauthorized\"}, status_code=401)\n return response(scope, receive, send)\nreturn self.app(scope, receive, send)\n```\n\nThe request `scope` includes the request\u0027s `Host:` header and reconstructs the URL as shown below:\n\n```py\nf\"{scheme}://{host_header}{path}\"\n```\n\nNeither starlette nor [any of the ASGI servers](https://asgi.readthedocs.io/en/latest/implementations.html#servers) (including uvicorn, which vllm uses) properly filter the `Host:` header for invalid characters. This allows an attacker to include special URL characters such as `/` or `?` in the `Host:` header and thereby control the reconstructed URL and it\u0027s `.path` attribute.\n\nFastAPI/starlette\u0027s routing uses the HTTP path and does not depend on the parsed url.path attribute, allowing attackers to reach an endpoint via a certain path while providing a different value in the `.path`.\n\n### Impact\n- Instances of vllm that use an API Key for the OpenAI API and expose the API to attackers.\n- Instances behind an RFC-conforming web server (such as nginx) are **not** affected.",
"id": "GHSA-94f4-hr76-p5j6",
"modified": "2026-09-01T15:30:49Z",
"published": "2026-06-16T17:36:41Z",
"references": [
{
"type": "WEB",
"url": "https://github.com/vllm-project/vllm/security/advisories/GHSA-94f4-hr76-p5j6"
},
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-48746"
},
{
"type": "WEB",
"url": "https://github.com/vllm-project/vllm/pull/43426"
},
{
"type": "WEB",
"url": "https://x41-dsec.de/lab/advisories/x41-2026-002-starlette"
},
{
"type": "WEB",
"url": "https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-48746.json"
},
{
"type": "PACKAGE",
"url": "https://github.com/vllm-project/vllm"
},
{
"type": "WEB",
"url": "https://github.com/pypa/advisory-database/tree/main/vulns/vllm/PYSEC-2026-226.yaml"
},
{
"type": "WEB",
"url": "https://bugzilla.redhat.com/show_bug.cgi?id=2491581"
},
{
"type": "WEB",
"url": "https://access.redhat.com/security/cve/CVE-2026-48746"
},
{
"type": "WEB",
"url": "https://access.redhat.com/errata/RHSA-2026:61629"
},
{
"type": "WEB",
"url": "https://access.redhat.com/errata/RHSA-2026:61627"
},
{
"type": "WEB",
"url": "https://access.redhat.com/errata/RHSA-2026:43038"
},
{
"type": "WEB",
"url": "https://access.redhat.com/errata/RHSA-2026:42644"
},
{
"type": "WEB",
"url": "https://access.redhat.com/errata/RHSA-2026:42142"
},
{
"type": "WEB",
"url": "https://access.redhat.com/errata/RHSA-2026:42132"
},
{
"type": "WEB",
"url": "https://access.redhat.com/errata/RHSA-2026:36006"
},
{
"type": "WEB",
"url": "https://access.redhat.com/errata/RHSA-2026:36005"
},
{
"type": "WEB",
"url": "https://access.redhat.com/errata/RHSA-2026:30089"
},
{
"type": "WEB",
"url": "https://access.redhat.com/errata/RHSA-2026:30088"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H",
"type": "CVSS_V3"
}
],
"summary": "vLLM: OpenAI auth bypass"
}
GHSA-9548-QRRJ-X5PJ
Vulnerability from github – Published: 2025-07-14 19:33 – Updated: 2025-07-15 00:34Summary
The Python parser is vulnerable to a request smuggling vulnerability due to not parsing trailer sections of an HTTP request.
Impact
If a pure Python version of aiohttp is installed (i.e. without the usual C extensions) or AIOHTTP_NO_EXTENSIONS is enabled, then an attacker may be able to execute a request smuggling attack to bypass certain firewalls or proxy protections.
Patch: https://github.com/aio-libs/aiohttp/commit/e8d774f635dc6d1cd3174d0e38891da5de0e2b6a
{
"affected": [
{
"package": {
"ecosystem": "PyPI",
"name": "aiohttp"
},
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"fixed": "3.12.14"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [
"CVE-2025-53643"
],
"database_specific": {
"cwe_ids": [
"CWE-444"
],
"github_reviewed": true,
"github_reviewed_at": "2025-07-14T19:33:31Z",
"nvd_published_at": "2025-07-14T21:15:27Z",
"severity": "LOW"
},
"details": "### Summary\nThe Python parser is vulnerable to a request smuggling vulnerability due to not parsing trailer sections of an HTTP request.\n\n### Impact\nIf a pure Python version of aiohttp is installed (i.e. without the usual C extensions) or AIOHTTP_NO_EXTENSIONS is enabled, then an attacker may be able to execute a request smuggling attack to bypass certain firewalls or proxy protections.\n\n----\n\nPatch: https://github.com/aio-libs/aiohttp/commit/e8d774f635dc6d1cd3174d0e38891da5de0e2b6a",
"id": "GHSA-9548-qrrj-x5pj",
"modified": "2025-07-15T00:34:20Z",
"published": "2025-07-14T19:33:31Z",
"references": [
{
"type": "WEB",
"url": "https://github.com/aio-libs/aiohttp/security/advisories/GHSA-9548-qrrj-x5pj"
},
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2025-53643"
},
{
"type": "WEB",
"url": "https://github.com/aio-libs/aiohttp/commit/e8d774f635dc6d1cd3174d0e38891da5de0e2b6a"
},
{
"type": "PACKAGE",
"url": "https://github.com/aio-libs/aiohttp"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:U",
"type": "CVSS_V4"
}
],
"summary": " AIOHTTP is vulnerable to HTTP Request/Response Smuggling through incorrect parsing of chunked trailer sections"
}
GHSA-9667-7P67-2364
Vulnerability from github – Published: 2026-06-17 21:34 – Updated: 2026-06-17 21:34Tinyproxy through 1.11.3, fixed in commit ff45d3b, fails to reconcile conflicting Content-Length and Transfer-Encoding: chunked headers, forwarding both verbatim to the backend while using Content-Length to determine how many request body bytes to consume. Remote attackers can desynchronize the proxy and backend parser state, allowing injection of arbitrary HTTP requests to the backend to enable cache poisoning, access control bypass, and request hijacking.
{
"affected": [],
"aliases": [
"CVE-2026-54387"
],
"database_specific": {
"cwe_ids": [
"CWE-444"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2026-06-17T20:17:27Z",
"severity": "CRITICAL"
},
"details": "Tinyproxy through 1.11.3, fixed in commit ff45d3b, fails to reconcile conflicting Content-Length and Transfer-Encoding: chunked headers, forwarding both verbatim to the backend while using Content-Length to determine how many request body bytes to consume. Remote attackers can desynchronize the proxy and backend parser state, allowing injection of arbitrary HTTP requests to the backend to enable cache poisoning, access control bypass, and request hijacking.",
"id": "GHSA-9667-7p67-2364",
"modified": "2026-06-17T21:34:39Z",
"published": "2026-06-17T21:34:39Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-54387"
},
{
"type": "WEB",
"url": "https://github.com/tinyproxy/tinyproxy/issues/609"
},
{
"type": "WEB",
"url": "https://github.com/tinyproxy/tinyproxy/pull/610"
},
{
"type": "WEB",
"url": "https://github.com/tinyproxy/tinyproxy/commit/ff45d3bf0e61d0f8ed97ab379d3047f04eb67521"
},
{
"type": "WEB",
"url": "https://www.vulncheck.com/advisories/tinyproxy-http-request-smuggling-via-cl-te-desynchronization"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N",
"type": "CVSS_V3"
},
{
"score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X",
"type": "CVSS_V4"
}
]
}
GHSA-968F-66R5-5V74
Vulnerability from github – Published: 2020-01-06 18:44 – Updated: 2024-11-19 13:58Impact
The patches introduced to fix https://github.com/Pylons/waitress/security/advisories/GHSA-m5ff-3wj3-8ph4 were not complete and still would allow an attacker to smuggle requests/split a HTTP request with invalid data.
This updates the existing CVE with ID: CVE-2019-16789
Patches
Waitress version 1.4.2 has been updated to now validate HTTP headers better to avoid the issue, completely fixing all known issues with whitespace.
Workarounds
There are no work-arounds, upgrading to Waitress 1.4.2 is highly recommended.
References
See https://github.com/Pylons/waitress/security/advisories/GHSA-m5ff-3wj3-8ph4 for more information on the security issue.
For more information
If you have any questions or comments about this advisory:
- open an issue at https://github.com/Pylons/waitress/issues (if not sensitive or security related)
- email the Pylons Security mailing list: pylons-project-security@googlegroups.com (if security related)
{
"affected": [
{
"package": {
"ecosystem": "PyPI",
"name": "waitress"
},
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"fixed": "1.4.2"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [
"CVE-2019-16789"
],
"database_specific": {
"cwe_ids": [
"CWE-444"
],
"github_reviewed": true,
"github_reviewed_at": "2020-01-06T18:43:11Z",
"nvd_published_at": "2019-12-26T17:15:00Z",
"severity": "MODERATE"
},
"details": "### Impact\n\nThe patches introduced to fix https://github.com/Pylons/waitress/security/advisories/GHSA-m5ff-3wj3-8ph4 were not complete and still would allow an attacker to smuggle requests/split a HTTP request with invalid data.\n\nThis updates the existing CVE with ID: CVE-2019-16789\n\n### Patches\n\nWaitress version 1.4.2 has been updated to now validate HTTP headers better to avoid the issue, completely fixing all known issues with whitespace.\n\n### Workarounds\n\nThere are no work-arounds, upgrading to Waitress 1.4.2 is highly recommended.\n\n### References\n\nSee https://github.com/Pylons/waitress/security/advisories/GHSA-m5ff-3wj3-8ph4 for more information on the security issue.\n\n### For more information\n\nIf you have any questions or comments about this advisory:\n\n* open an issue at https://github.com/Pylons/waitress/issues (if not sensitive or security related)\n* email the Pylons Security mailing list: pylons-project-security@googlegroups.com (if security related)",
"id": "GHSA-968f-66r5-5v74",
"modified": "2024-11-19T13:58:27Z",
"published": "2020-01-06T18:44:21Z",
"references": [
{
"type": "WEB",
"url": "https://github.com/Pylons/waitress/security/advisories/GHSA-968f-66r5-5v74"
},
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2019-16789"
},
{
"type": "WEB",
"url": "https://github.com/github/advisory-review/pull/14604"
},
{
"type": "WEB",
"url": "https://github.com/Pylons/waitress/commit/11d9e138125ad46e951027184b13242a3c1de017"
},
{
"type": "WEB",
"url": "https://github.com/Pylons/waitress/commit/ddb65b489d01d696afa1695b75fdd5df3e4ffdf8"
},
{
"type": "WEB",
"url": "https://access.redhat.com/errata/RHSA-2020:0720"
},
{
"type": "WEB",
"url": "https://docs.pylonsproject.org/projects/waitress/en/latest/#security-fixes"
},
{
"type": "PACKAGE",
"url": "https://github.com/Pylons/waitress"
},
{
"type": "ADVISORY",
"url": "https://github.com/advisories/GHSA-968f-66r5-5v74"
},
{
"type": "WEB",
"url": "https://github.com/pypa/advisory-database/tree/main/vulns/waitress/PYSEC-2019-138.yaml"
},
{
"type": "WEB",
"url": "https://lists.debian.org/debian-lts-announce/2022/05/msg00011.html"
},
{
"type": "WEB",
"url": "https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/GVDHR2DNKCNQ7YQXISJ45NT4IQDX3LJ7"
},
{
"type": "WEB",
"url": "https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/LYEOTGWJZVKPRXX2HBNVIYWCX73QYPM5"
},
{
"type": "WEB",
"url": "https://www.oracle.com/security-alerts/cpuapr2022.html"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:L/I:H/A:N",
"type": "CVSS_V3"
},
{
"score": "CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:N/VI:N/VA:N/SC:L/SI:H/SA:N",
"type": "CVSS_V4"
}
],
"summary": "HTTP Request Smuggling in Waitress: Invalid whitespace characters in headers (Follow-up)"
}
GHSA-974X-WV37-RCCW
Vulnerability from github – Published: 2026-07-01 00:34 – Updated: 2026-07-29 21:30IBM WebSphere Application Server 9.0, and 8.5 and IBM WebSphere Application Server - Liberty 17.0.0.3 through 26.0.0.6 are affected by an HTTP request smuggling vulnerability.
{
"affected": [],
"aliases": [
"CVE-2026-11541"
],
"database_specific": {
"cwe_ids": [
"CWE-444"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2026-06-30T22:16:46Z",
"severity": "HIGH"
},
"details": "IBM WebSphere Application Server 9.0, and 8.5 and IBM WebSphere Application Server - Liberty 17.0.0.3 through 26.0.0.6 are affected by an HTTP request smuggling vulnerability.",
"id": "GHSA-974x-wv37-rccw",
"modified": "2026-07-29T21:30:47Z",
"published": "2026-07-01T00:34:00Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-11541"
},
{
"type": "WEB",
"url": "https://www.ibm.com/support/pages/node/7277550"
},
{
"type": "WEB",
"url": "https://www.ibm.com/support/pages/node/7281750"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N",
"type": "CVSS_V3"
}
]
}
GHSA-984C-QJ5W-FV7J
Vulnerability from github – Published: 2026-08-05 18:31 – Updated: 2026-08-05 18:31An HTTP request smuggling vulnerability in the HTTP App Server of Progress MarkLogic Server before 11.3.6 and 12.0.3 allows a remote attacker to bypass authentication and authorization checks, hijack a legitimate user's session, or capture credentials. The vulnerability occurs when a crafted HTTP request containing both Content-Length and Transfer-Encoding headers causes a reverse proxy and MarkLogic Server to interpret request boundaries differently.
{
"affected": [],
"aliases": [
"CVE-2026-9190"
],
"database_specific": {
"cwe_ids": [
"CWE-444"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2026-08-05T16:17:09Z",
"severity": "CRITICAL"
},
"details": "An HTTP request smuggling vulnerability in the HTTP App Server of Progress MarkLogic Server before 11.3.6 and 12.0.3 allows a remote attacker to bypass authentication and authorization checks, hijack a legitimate user\u0027s session, or capture credentials. The vulnerability occurs when a crafted HTTP request containing both Content-Length and Transfer-Encoding headers causes a reverse proxy and MarkLogic Server to interpret request boundaries differently.",
"id": "GHSA-984c-qj5w-fv7j",
"modified": "2026-08-05T18:31:37Z",
"published": "2026-08-05T18:31:37Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-9190"
},
{
"type": "WEB",
"url": "https://community.progress.com/s/article/Marklogic-Critical-Security-Alert-Bulletin-August-2026"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N",
"type": "CVSS_V3"
}
]
}
Mitigation
Use a web server that employs a strict HTTP parsing procedure, such as Apache [REF-433].
Mitigation
Use only SSL communication.
Mitigation
Terminate the client session after each request.
Mitigation
Turn all pages to non-cacheable.
CAPEC-273: HTTP Response Smuggling
An adversary manipulates and injects malicious content in the form of secret unauthorized HTTP responses, into a single HTTP response from a vulnerable or compromised back-end HTTP agent (e.g., server).
See CanPrecede relationships for possible consequences.
CAPEC-33: HTTP Request Smuggling
An adversary abuses the flexibility and discrepancies in the parsing and interpretation of HTTP Request messages using various HTTP headers, request-line and body parameters as well as message sizes (denoted by the end of message signaled by a given HTTP header) by different intermediary HTTP agents (e.g., load balancer, reverse proxy, web caching proxies, application firewalls, etc.) to secretly send unauthorized and malicious HTTP requests to a back-end HTTP agent (e.g., web server).
See CanPrecede relationships for possible consequences.