Vulnerability-Lookup

Vulnerability from cleanstart

Published

2026-09-04 00:46

Modified

2026-09-03 12:48

Summary

Netty is a network application framework for development of protocol servers and clients

Details

Multiple security vulnerabilities affect the keycloak package. Netty is a network application framework for development of protocol servers and clients. See references for individual vulnerability details.

Severity

9.8 (Critical)


                    
                      CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

References

URL

Type

	https://github.com/cleanstart-dev/cleanstart-secu…	ADVISORY
	https://osv.dev/vulnerability/CVE-2026-44249	WEB
	https://osv.dev/vulnerability/CVE-2026-44893	WEB
	https://osv.dev/vulnerability/CVE-2026-45416	WEB
	https://osv.dev/vulnerability/CVE-2026-45536	WEB
	https://osv.dev/vulnerability/CVE-2026-45673	WEB
	https://osv.dev/vulnerability/CVE-2026-45674	WEB
	https://osv.dev/vulnerability/CVE-2026-47244	WEB
	https://osv.dev/vulnerability/CVE-2026-47691	WEB
	https://osv.dev/vulnerability/CVE-2026-48043	WEB
	https://osv.dev/vulnerability/CVE-2026-48059	WEB
	https://osv.dev/vulnerability/CVE-2026-50010	WEB
	https://osv.dev/vulnerability/CVE-2026-50020	WEB
	https://osv.dev/vulnerability/CVE-2026-50560	WEB
	https://osv.dev/vulnerability/CVE-2026-6860	WEB
	https://osv.dev/vulnerability/ghsa-3qp7-7mw8-wx86	WEB
	https://osv.dev/vulnerability/ghsa-563q-j3cm-6jxm	WEB
	https://osv.dev/vulnerability/ghsa-5pvg-856g-cp85	WEB
	https://osv.dev/vulnerability/ghsa-5x3r-wrvg-rp6q	WEB
	https://osv.dev/vulnerability/ghsa-676x-f7gg-47vc	WEB
	https://osv.dev/vulnerability/ghsa-c2gf-v879-257j	WEB
	https://osv.dev/vulnerability/ghsa-cc37-9q2j-3hfv	WEB
	https://osv.dev/vulnerability/ghsa-h2qv-fj59-j46j	WEB
	https://osv.dev/vulnerability/ghsa-x4gw-5cx5-pgmh	WEB
	https://osv.dev/vulnerability/ghsa-xmv7-r254-6q78	WEB
	https://nvd.nist.gov/vuln/detail/CVE-2026-44249	WEB
	https://nvd.nist.gov/vuln/detail/CVE-2026-44893	WEB
	https://nvd.nist.gov/vuln/detail/CVE-2026-45416	WEB
	https://nvd.nist.gov/vuln/detail/CVE-2026-45536	WEB
	https://nvd.nist.gov/vuln/detail/CVE-2026-45673	WEB
	https://nvd.nist.gov/vuln/detail/CVE-2026-45674	WEB
	https://nvd.nist.gov/vuln/detail/CVE-2026-47244	WEB
	https://nvd.nist.gov/vuln/detail/CVE-2026-47691	WEB
	https://nvd.nist.gov/vuln/detail/CVE-2026-48043	WEB
	https://nvd.nist.gov/vuln/detail/CVE-2026-48059	WEB
	https://nvd.nist.gov/vuln/detail/CVE-2026-50010	WEB
	https://nvd.nist.gov/vuln/detail/CVE-2026-50020	WEB
	https://nvd.nist.gov/vuln/detail/CVE-2026-50560	WEB
	https://nvd.nist.gov/vuln/detail/CVE-2026-6860	WEB

JSON

To clipboard

{
  "affected": [
    {
      "package": {
        "ecosystem": "CleanStart",
        "name": "keycloak"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "26.4.2-r0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "credits": [],
  "database_specific": {},
  "details": "Multiple security vulnerabilities affect the keycloak package. Netty is a network application framework for development of protocol servers and clients. See references for individual vulnerability details.",
  "id": "CLEANSTART-2026-ZB03263",
  "modified": "2026-09-03T12:48:08Z",
  "published": "2026-09-04T00:46:48.827161Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://github.com/cleanstart-dev/cleanstart-security-advisories/tree/main/advisories/2026/CLEANSTART-2026-ZB03263.json"
    },
    {
      "type": "WEB",
      "url": "https://osv.dev/vulnerability/CVE-2026-44249"
    },
    {
      "type": "WEB",
      "url": "https://osv.dev/vulnerability/CVE-2026-44893"
    },
    {
      "type": "WEB",
      "url": "https://osv.dev/vulnerability/CVE-2026-45416"
    },
    {
      "type": "WEB",
      "url": "https://osv.dev/vulnerability/CVE-2026-45536"
    },
    {
      "type": "WEB",
      "url": "https://osv.dev/vulnerability/CVE-2026-45673"
    },
    {
      "type": "WEB",
      "url": "https://osv.dev/vulnerability/CVE-2026-45674"
    },
    {
      "type": "WEB",
      "url": "https://osv.dev/vulnerability/CVE-2026-47244"
    },
    {
      "type": "WEB",
      "url": "https://osv.dev/vulnerability/CVE-2026-47691"
    },
    {
      "type": "WEB",
      "url": "https://osv.dev/vulnerability/CVE-2026-48043"
    },
    {
      "type": "WEB",
      "url": "https://osv.dev/vulnerability/CVE-2026-48059"
    },
    {
      "type": "WEB",
      "url": "https://osv.dev/vulnerability/CVE-2026-50010"
    },
    {
      "type": "WEB",
      "url": "https://osv.dev/vulnerability/CVE-2026-50020"
    },
    {
      "type": "WEB",
      "url": "https://osv.dev/vulnerability/CVE-2026-50560"
    },
    {
      "type": "WEB",
      "url": "https://osv.dev/vulnerability/CVE-2026-6860"
    },
    {
      "type": "WEB",
      "url": "https://osv.dev/vulnerability/ghsa-3qp7-7mw8-wx86"
    },
    {
      "type": "WEB",
      "url": "https://osv.dev/vulnerability/ghsa-563q-j3cm-6jxm"
    },
    {
      "type": "WEB",
      "url": "https://osv.dev/vulnerability/ghsa-5pvg-856g-cp85"
    },
    {
      "type": "WEB",
      "url": "https://osv.dev/vulnerability/ghsa-5x3r-wrvg-rp6q"
    },
    {
      "type": "WEB",
      "url": "https://osv.dev/vulnerability/ghsa-676x-f7gg-47vc"
    },
    {
      "type": "WEB",
      "url": "https://osv.dev/vulnerability/ghsa-c2gf-v879-257j"
    },
    {
      "type": "WEB",
      "url": "https://osv.dev/vulnerability/ghsa-cc37-9q2j-3hfv"
    },
    {
      "type": "WEB",
      "url": "https://osv.dev/vulnerability/ghsa-h2qv-fj59-j46j"
    },
    {
      "type": "WEB",
      "url": "https://osv.dev/vulnerability/ghsa-x4gw-5cx5-pgmh"
    },
    {
      "type": "WEB",
      "url": "https://osv.dev/vulnerability/ghsa-xmv7-r254-6q78"
    },
    {
      "type": "WEB",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-44249"
    },
    {
      "type": "WEB",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-44893"
    },
    {
      "type": "WEB",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-45416"
    },
    {
      "type": "WEB",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-45536"
    },
    {
      "type": "WEB",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-45673"
    },
    {
      "type": "WEB",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-45674"
    },
    {
      "type": "WEB",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-47244"
    },
    {
      "type": "WEB",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-47691"
    },
    {
      "type": "WEB",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-48043"
    },
    {
      "type": "WEB",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-48059"
    },
    {
      "type": "WEB",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-50010"
    },
    {
      "type": "WEB",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-50020"
    },
    {
      "type": "WEB",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-50560"
    },
    {
      "type": "WEB",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-6860"
    }
  ],
  "related": [],
  "schema_version": "1.7.3",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
      "type": "CVSS_V3"
    }
  ],
  "summary": "Netty is a network application framework for development of protocol servers and clients",
  "upstream": [
    "CVE-2026-44249",
    "CVE-2026-44893",
    "CVE-2026-45416",
    "CVE-2026-45536",
    "CVE-2026-45673",
    "CVE-2026-45674",
    "CVE-2026-47244",
    "CVE-2026-47691",
    "CVE-2026-48043",
    "CVE-2026-48059",
    "CVE-2026-50010",
    "CVE-2026-50020",
    "CVE-2026-50560",
    "CVE-2026-6860",
    "ghsa-3qp7-7mw8-wx86",
    "ghsa-563q-j3cm-6jxm",
    "ghsa-5pvg-856g-cp85",
    "ghsa-5x3r-wrvg-rp6q",
    "ghsa-676x-f7gg-47vc",
    "ghsa-c2gf-v879-257j",
    "ghsa-cc37-9q2j-3hfv",
    "ghsa-h2qv-fj59-j46j",
    "ghsa-x4gw-5cx5-pgmh",
    "ghsa-xmv7-r254-6q78"
  ]
}

GHSA-CC37-9Q2J-3HFV

Vulnerability from github – Published: 2026-06-08 19:02 – Updated: 2026-06-12 19:29

Summary

Netty: HAProxy SSL TLV parsing leaks retained slice on invalid TLV length

Details

When decoding a PP2_TYPE_SSL TLV, HAProxyMessage.readNextTLV() first calls header.retainedSlice(header.readerIndex(), length) and only then reads the 1-byte client field and 4-byte verify field. If the attacker sets the TLV length below 5, the subsequent readByte/readInt throws IndexOutOfBoundsException. HAProxyMessageDecoder only catches HAProxyProtocolException around this call, so the IOOBE propagates and the retained slice on the pooled cumulation buffer is never released.

Severity

7.5 (High)


                  
                    CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Show details on source website

JSON

To clipboard

{
  "affected": [
    {
      "database_specific": {
        "last_known_affected_version_range": "\u003c= 4.2.14.Final"
      },
      "package": {
        "ecosystem": "Maven",
        "name": "io.netty:netty-codec-haproxy"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "4.2.0.Final"
            },
            {
              "fixed": "4.2.15.Final"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "database_specific": {
        "last_known_affected_version_range": "\u003c= 4.1.134.Final"
      },
      "package": {
        "ecosystem": "Maven",
        "name": "io.netty:netty-codec-haproxy"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "4.1.135.Final"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-44893"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-703"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-06-08T19:02:21Z",
    "nvd_published_at": "2026-06-12T15:16:26Z",
    "severity": "HIGH"
  },
  "details": "When decoding a PP2_TYPE_SSL TLV, HAProxyMessage.readNextTLV() first calls `header.retainedSlice(header.readerIndex(), length)` and only then reads the 1-byte client field and 4-byte verify field. If the attacker sets the TLV length below 5, the subsequent readByte/readInt throws IndexOutOfBoundsException. HAProxyMessageDecoder only catches HAProxyProtocolException around this call, so the IOOBE propagates and the retained slice on the pooled cumulation buffer is never released.",
  "id": "GHSA-cc37-9q2j-3hfv",
  "modified": "2026-06-12T19:29:14Z",
  "published": "2026-06-08T19:02:21Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/netty/netty/security/advisories/GHSA-cc37-9q2j-3hfv"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-44893"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/netty/netty"
    },
    {
      "type": "WEB",
      "url": "https://github.com/netty/netty/releases/tag/netty-4.1.135.Final"
    },
    {
      "type": "WEB",
      "url": "https://github.com/netty/netty/releases/tag/netty-4.2.15.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: HAProxy SSL TLV parsing leaks retained slice on invalid TLV length"
}

GHSA-H2QV-FJ59-J46J

Vulnerability from github – Published: 2026-06-11 20:19 – Updated: 2026-08-13 15:34

Summary

Netty HAProxy: Unbalanced Reference Count in Nested PP2_TYPE_SSL TLV Parsing Leads to Memory Exhaustion

Details

Impact

The HAProxy PROXY protocol v2 codec in netty leaks native or heap memory on every connection when a client sends a syntactically valid header containing nested PP2_TYPE_SSL TLVs (type-length-value records) at depth two or greater. The leak occurs on the successful parse path — no exception is thrown, the message fires downstream, the decoder removes itself, and the application releases the HAProxyMessage normally. Yet the underlying cumulation buffer (a pooled, potentially direct ByteBuf allocated by the channel) remains permanently pinned.

Severity

7.5 (High)


                  
                    CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

8.7 (High)


                  
                    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

Show details on source website

JSON

To clipboard

{
  "affected": [
    {
      "database_specific": {
        "last_known_affected_version_range": "\u003c= 4.2.14.Final"
      },
      "package": {
        "ecosystem": "Maven",
        "name": "io.netty:netty-codec-haproxy"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "4.2.0.Final"
            },
            {
              "fixed": "4.2.15.Final"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "database_specific": {
        "last_known_affected_version_range": "\u003c= 4.1.134.Final"
      },
      "package": {
        "ecosystem": "Maven",
        "name": "io.netty:netty-codec-haproxy"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "4.1.135.Final"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-48059"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-1286",
      "CWE-401"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-06-11T20:19:27Z",
    "nvd_published_at": "2026-06-12T16:16:30Z",
    "severity": "HIGH"
  },
  "details": "### Impact\nThe HAProxy PROXY protocol v2 codec in netty leaks native or heap memory on every connection when a client sends a syntactically valid header containing nested `PP2_TYPE_SSL` TLVs (type-length-value records) at depth two or greater. The leak occurs on the successful parse path \u2014 no exception is thrown, the message fires downstream, the decoder removes itself, and the application releases the `HAProxyMessage` normally. Yet the underlying cumulation buffer (a pooled, potentially direct `ByteBuf` allocated by the channel) remains permanently pinned.",
  "id": "GHSA-h2qv-fj59-j46j",
  "modified": "2026-08-13T15:34:09Z",
  "published": "2026-06-11T20:19:27Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/netty/netty/security/advisories/GHSA-h2qv-fj59-j46j"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-48059"
    },
    {
      "type": "WEB",
      "url": "https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-48059.json"
    },
    {
      "type": "WEB",
      "url": "https://github.com/netty/netty/releases/tag/netty-4.2.15.Final"
    },
    {
      "type": "WEB",
      "url": "https://github.com/netty/netty/releases/tag/netty-4.1.135.Final"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/netty/netty"
    },
    {
      "type": "WEB",
      "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2488437"
    },
    {
      "type": "WEB",
      "url": "https://access.redhat.com/security/cve/CVE-2026-48059"
    },
    {
      "type": "WEB",
      "url": "https://access.redhat.com/errata/RHSA-2026:54435"
    },
    {
      "type": "WEB",
      "url": "https://access.redhat.com/errata/RHSA-2026:53806"
    },
    {
      "type": "WEB",
      "url": "https://access.redhat.com/errata/RHSA-2026:53644"
    },
    {
      "type": "WEB",
      "url": "https://access.redhat.com/errata/RHSA-2026:50085"
    },
    {
      "type": "WEB",
      "url": "https://access.redhat.com/errata/RHSA-2026:48151"
    },
    {
      "type": "WEB",
      "url": "https://access.redhat.com/errata/RHSA-2026:41951"
    },
    {
      "type": "WEB",
      "url": "https://access.redhat.com/errata/RHSA-2026:37390"
    },
    {
      "type": "WEB",
      "url": "https://access.redhat.com/errata/RHSA-2026:36820"
    },
    {
      "type": "WEB",
      "url": "https://access.redhat.com/errata/RHSA-2026:34608"
    },
    {
      "type": "WEB",
      "url": "https://access.redhat.com/errata/RHSA-2026:26586"
    },
    {
      "type": "WEB",
      "url": "https://access.redhat.com/errata/RHSA-2026:26018"
    },
    {
      "type": "WEB",
      "url": "https://access.redhat.com/errata/RHSA-2026:26017"
    }
  ],
  "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"
    },
    {
      "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 HAProxy: Unbalanced Reference Count in Nested PP2_TYPE_SSL TLV Parsing Leads to Memory Exhaustion"
}

GHSA-X4GW-5CX5-PGMH

Vulnerability from github – Published: 2026-06-08 23:01 – Updated: 2026-06-12 19:29

Summary

Netty: SNI handler pre-allocates up to 16 MiB from nine attacker bytes

Details

SslClientHelloHandler.decode() reads the 24-bit TLS handshake length and, when the ClientHello does not fit in the first record, eagerly allocates ctx.alloc().buffer(handshakeLength) (line 161). The guard at line 140 is handshakeLength > maxClientHelloLength && maxClientHelloLength != 0, and the commonly-used SniHandler/AbstractSniHandler constructors (SniHandler(Mapping), SniHandler(AsyncMapping), AbstractSniHandler()) pass maxClientHelloLength=0 and handshakeTimeoutMillis=0, so the length guard is disabled and no timeout is scheduled. A 16 MiB request exceeds the default pooled chunk size and becomes a huge/unpooled allocation performed immediately. The buffer is retained in the handler until the channel closes.

Severity

7.5 (High)


                  
                    CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Show details on source website

JSON

To clipboard

{
  "affected": [
    {
      "database_specific": {
        "last_known_affected_version_range": "\u003c= 4.2.14.Final"
      },
      "package": {
        "ecosystem": "Maven",
        "name": "io.netty:netty-handler"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "4.2.0.Final"
            },
            {
              "fixed": "4.2.15.Final"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "database_specific": {
        "last_known_affected_version_range": "\u003c= 4.1.134.Final"
      },
      "package": {
        "ecosystem": "Maven",
        "name": "io.netty:netty-handler"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "4.1.135.Final"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-45416"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-770"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-06-08T23:01:04Z",
    "nvd_published_at": "2026-06-12T15:16:26Z",
    "severity": "HIGH"
  },
  "details": "SslClientHelloHandler.decode() reads the 24-bit TLS handshake length and, when the ClientHello does not fit in the first record, eagerly allocates `ctx.alloc().buffer(handshakeLength)` (line 161). The guard at line 140 is `handshakeLength \u003e maxClientHelloLength \u0026\u0026 maxClientHelloLength != 0`, and the commonly-used SniHandler/AbstractSniHandler constructors (SniHandler(Mapping), SniHandler(AsyncMapping), AbstractSniHandler()) pass maxClientHelloLength=0 and handshakeTimeoutMillis=0, so the length guard is disabled and no timeout is scheduled. A 16 MiB request exceeds the default pooled chunk size and becomes a huge/unpooled allocation performed immediately. The buffer is retained in the handler until the channel closes.",
  "id": "GHSA-x4gw-5cx5-pgmh",
  "modified": "2026-06-12T19:29:22Z",
  "published": "2026-06-08T23:01:04Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/netty/netty/security/advisories/GHSA-x4gw-5cx5-pgmh"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-45416"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/netty/netty"
    },
    {
      "type": "WEB",
      "url": "https://github.com/netty/netty/releases/tag/netty-4.1.135.Final"
    },
    {
      "type": "WEB",
      "url": "https://github.com/netty/netty/releases/tag/netty-4.2.15.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: SNI handler pre-allocates up to 16 MiB from nine attacker bytes"
}

GHSA-XMV7-R254-6Q78

Vulnerability from github – Published: 2026-06-08 23:02 – Updated: 2026-06-12 19:29

Summary

Netty: DNS Cache Poisoning due to Predictable PRNG and Default Static Source Port

Details

Summary

Netty's DNS resolver uses a predictable PRNG for generating DNS transaction IDs and defaults to a static UDP source port. This combination reduces the entropy of DNS queries, enabling DNS Cache Poisoning (Kaminsky attack).

Details

Two factors contribute to this vulnerability in io.netty.resolver.dns: - Predictable Query IDs: DnsQueryIdSpace manages 16-bit transaction IDs in buckets of 16,384 IDs. It initializes only the first bucket. When an ID is returned, it is pushed back into the bucket at a random index generated by java.util.concurrent.ThreadLocalRandom:

Random random = ThreadLocalRandom.current();
int insertionPosition = random.nextInt(count + 1);

Because ThreadLocalRandom is a predictable LCG and the resolver operates within a single bucket, the sequence of IDs is predictable once the PRNG state is mathematically recovered.

Default Static Source Port: DnsNameResolverBuilder defaults to a channelStrategy of ChannelPerResolver. This binds the DatagramChannel once, resulting in a static source port for all subsequent queries.

Combined, a static source port and predictable transaction IDs reduces the entropy required to secure DNS resolution against spoofing.

Impact

DNS Cache Poisoning. Downstream applications using the default Netty DNS resolver may connect to malicious IPs, leading to traffic interception or MitM attacks.

Severity

6.8 (Medium)


                  
                    CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:N/I:H/A:N

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{
  "affected": [
    {
      "database_specific": {
        "last_known_affected_version_range": "\u003c= 4.2.14.Final"
      },
      "package": {
        "ecosystem": "Maven",
        "name": "io.netty:netty-resolver-dns"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "4.2.0.Final"
            },
            {
              "fixed": "4.2.15.Final"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "database_specific": {
        "last_known_affected_version_range": "\u003c= 4.1.134.Final"
      },
      "package": {
        "ecosystem": "Maven",
        "name": "io.netty:netty-resolver-dns"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "4.1.135.Final"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-45673"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-330",
      "CWE-340"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-06-08T23:02:05Z",
    "nvd_published_at": "2026-06-12T15:16:27Z",
    "severity": "MODERATE"
  },
  "details": "### Summary\nNetty\u0027s DNS resolver uses a predictable PRNG for generating DNS transaction IDs and defaults to a static UDP source port. This combination reduces the entropy of DNS queries, enabling DNS Cache Poisoning (Kaminsky attack).\n\n### Details\nTwo factors contribute to this vulnerability in io.netty.resolver.dns:\n- Predictable Query IDs: `DnsQueryIdSpace` manages 16-bit transaction IDs in buckets of 16,384 IDs. It initializes only the first bucket. When an ID is returned, it is pushed back into the bucket at a random index generated by java.util.concurrent.ThreadLocalRandom:\n\n```java\nRandom random = ThreadLocalRandom.current();\nint insertionPosition = random.nextInt(count + 1);\n```\n\nBecause ThreadLocalRandom is a predictable LCG and the resolver operates within a single bucket, the sequence of IDs is predictable once the PRNG state is mathematically recovered.\n\n- Default Static Source Port: `DnsNameResolverBuilder` defaults to a `channelStrategy` of `ChannelPerResolver`. This binds the DatagramChannel once, resulting in a static source port for all subsequent queries.\n\nCombined, a static source port and predictable transaction IDs reduces the entropy required to secure DNS resolution against spoofing.\n\n### Impact\nDNS Cache Poisoning. Downstream applications using the default Netty DNS resolver may connect to malicious IPs, leading to traffic interception or MitM attacks.",
  "id": "GHSA-xmv7-r254-6q78",
  "modified": "2026-06-12T19:29:30Z",
  "published": "2026-06-08T23:02:05Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/netty/netty/security/advisories/GHSA-xmv7-r254-6q78"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-45673"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/netty/netty"
    },
    {
      "type": "WEB",
      "url": "https://github.com/netty/netty/releases/tag/netty-4.1.135.Final"
    },
    {
      "type": "WEB",
      "url": "https://github.com/netty/netty/releases/tag/netty-4.2.15.Final"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:N/I:H/A:N",
      "type": "CVSS_V3"
    }
  ],
  "summary": "Netty: DNS Cache Poisoning due to Predictable PRNG and Default Static Source Port"
}

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.

Detection rules are retrieved from Rulezet.

The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.
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.

Action not permitted

Vulnerability from cleanstart

GHSA-CC37-9Q2J-3HFV

GHSA-H2QV-FJ59-J46J

Impact

GHSA-X4GW-5CX5-PGMH

GHSA-XMV7-R254-6Q78

Summary

Details

Impact

Tags

Sightings

Nomenclature