UBUNTU-CVE-2026-75595 (CVE-2026-75595)

Vulnerability from osv_ubuntu – Published: 2026-08-19 21:17 – Updated: 2026-09-23 23:35 – Source website
VLAI
Details

Netty is an asynchronous, event-driven network application framework. Prior to 4.1.137.Fina and 4.2.17.Final, io.netty.handler.ssl.SslClientHelloHandler#decode checks the wrong offset before reading the four-byte TLS handshake header, so a ClientHello whose handshake header spans records can cause an IndexOutOfBoundsException and invoke select(ctx, null). This selects the default SslContext instead of the SNI-specific context. In deployments where per-SNI clientAuth=REQUIRE is the sole mutual TLS gate, the default SslContext uses clientAuth=NONE or clientAuth=OPTIONAL, and no application-layer certificate verification exists, an unauthenticated remote attacker can bypass the protected route's mutual TLS requirement. This issue is fixed in versions 4.1.137.Final and 4.2.17.Final.

Severity
9.1 (Critical)
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N
9.1 (Critical)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
N/A (UNKNOWN)
medium
References
To clipboard 

{
  "affected": [
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "libnetty-java",
            "binary_version": "1:3.2.6.Final-2+deb8u2ubuntu0.1~esm1"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:Pro:14.04:LTS",
        "name": "netty",
        "purl": "pkg:deb/ubuntu/netty@1:3.2.6.Final-2+deb8u2ubuntu0.1~esm1?arch=source\u0026distro=esm-infra-legacy/trusty"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "1:3.2.6.Final-2",
        "1:3.2.6.Final-2+deb8u2build0.14.04.1~esm1",
        "1:3.2.6.Final-2+deb8u2ubuntu0.1~esm1"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "libnetty-java",
            "binary_version": "1:4.0.34-1ubuntu0.1~esm5"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:Pro:16.04:LTS",
        "name": "netty",
        "purl": "pkg:deb/ubuntu/netty@1:4.0.34-1ubuntu0.1~esm5?arch=source\u0026distro=esm-apps-legacy/xenial"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "1:3.2.6.Final-2",
        "1:4.0.32-1",
        "1:4.0.33-1",
        "1:4.0.34-1",
        "1:4.0.34-1ubuntu0.1~esm1",
        "1:4.0.34-1ubuntu0.1~esm2",
        "1:4.0.34-1ubuntu0.1~esm3",
        "1:4.0.34-1ubuntu0.1~esm4",
        "1:4.0.34-1ubuntu0.1~esm5"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "libnetty-java",
            "binary_version": "1:4.1.7-4ubuntu0.1+esm7"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:Pro:18.04:LTS",
        "name": "netty",
        "purl": "pkg:deb/ubuntu/netty@1:4.1.7-4ubuntu0.1+esm7?arch=source\u0026distro=esm-apps/bionic"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "1:4.1.7-4",
        "1:4.1.7-4ubuntu0.1~esm1",
        "1:4.1.7-4ubuntu0.1",
        "1:4.1.7-4ubuntu0.1+esm1",
        "1:4.1.7-4ubuntu0.1+esm2",
        "1:4.1.7-4ubuntu0.1+esm3",
        "1:4.1.7-4ubuntu0.1+esm4",
        "1:4.1.7-4ubuntu0.1+esm5",
        "1:4.1.7-4ubuntu0.1+esm6",
        "1:4.1.7-4ubuntu0.1+esm7"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "libnetty-java",
            "binary_version": "1:4.1.45-1ubuntu0.1~esm7"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:Pro:20.04:LTS",
        "name": "netty",
        "purl": "pkg:deb/ubuntu/netty@1:4.1.45-1ubuntu0.1~esm7?arch=source\u0026distro=esm-apps/focal"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "1:4.1.33-1",
        "1:4.1.33-2",
        "1:4.1.33-3",
        "1:4.1.45-1",
        "1:4.1.45-1ubuntu0.1~esm1",
        "1:4.1.45-1ubuntu0.1~esm2",
        "1:4.1.45-1ubuntu0.1~esm3",
        "1:4.1.45-1ubuntu0.1~esm4",
        "1:4.1.45-1ubuntu0.1~esm6",
        "1:4.1.45-1ubuntu0.1~esm7"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "libnetty-java",
            "binary_version": "1:4.1.48-4+deb11u2ubuntu0.2+esm1"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:Pro:22.04:LTS",
        "name": "netty",
        "purl": "pkg:deb/ubuntu/netty@1:4.1.48-4+deb11u2ubuntu0.2+esm1?arch=source\u0026distro=esm-apps/jammy"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "1:4.1.48-4",
        "1:4.1.48-4+deb11u1build0.22.04.1",
        "1:4.1.48-4+deb11u2build0.22.04.1",
        "1:4.1.48-4+deb11u2ubuntu0.1~esm1",
        "1:4.1.48-4+deb11u2ubuntu0.1~esm2",
        "1:4.1.48-4+deb11u2ubuntu0.1",
        "1:4.1.48-4+deb11u2ubuntu0.1+esm1",
        "1:4.1.48-4+deb11u2ubuntu0.1+esm3",
        "1:4.1.48-4+deb11u2ubuntu0.2",
        "1:4.1.48-4+deb11u2ubuntu0.2+esm1"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "libnetty-java",
            "binary_version": "1:4.1.48-9ubuntu0.2+esm2"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:Pro:24.04:LTS",
        "name": "netty",
        "purl": "pkg:deb/ubuntu/netty@1:4.1.48-9ubuntu0.2+esm2?arch=source\u0026distro=esm-apps/noble"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "1:4.1.48-7",
        "1:4.1.48-8",
        "1:4.1.48-9",
        "1:4.1.48-9ubuntu0.1~esm1",
        "1:4.1.48-9ubuntu0.1~esm2",
        "1:4.1.48-9ubuntu0.1",
        "1:4.1.48-9ubuntu0.1+esm1",
        "1:4.1.48-9ubuntu0.1+esm3",
        "1:4.1.48-9ubuntu0.2",
        "1:4.1.48-9ubuntu0.2+esm1",
        "1:4.1.48-9ubuntu0.2+esm2"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "libnetty-buffer-java",
            "binary_version": "1:4.1.48-16ubuntu0.1~esm2"
          },
          {
            "binary_name": "libnetty-common-java",
            "binary_version": "1:4.1.48-16ubuntu0.1~esm2"
          },
          {
            "binary_name": "libnetty-java",
            "binary_version": "1:4.1.48-16ubuntu0.1~esm2"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:Pro:26.04:LTS",
        "name": "netty",
        "purl": "pkg:deb/ubuntu/netty@1:4.1.48-16ubuntu0.1~esm2?arch=source\u0026distro=esm-apps/resolute"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "1:4.1.48-10",
        "1:4.1.48-11",
        "1:4.1.48-12",
        "1:4.1.48-13",
        "1:4.1.48-14",
        "1:4.1.48-16",
        "1:4.1.48-16ubuntu0.1~esm2"
      ]
    }
  ],
  "aliases": [],
  "details": "Netty is an asynchronous, event-driven network application framework. Prior to 4.1.137.Fina and 4.2.17.Final, io.netty.handler.ssl.SslClientHelloHandler#decode checks the wrong offset before reading the four-byte TLS handshake header, so a ClientHello whose handshake header spans records can cause an IndexOutOfBoundsException and invoke select(ctx, null). This selects the default SslContext instead of the SNI-specific context. In deployments where per-SNI clientAuth=REQUIRE is the sole mutual TLS gate, the default SslContext uses clientAuth=NONE or clientAuth=OPTIONAL, and no application-layer certificate verification exists, an unauthenticated remote attacker can bypass the protected route\u0027s mutual TLS requirement. This issue is fixed in versions 4.1.137.Final and 4.2.17.Final.",
  "id": "UBUNTU-CVE-2026-75595",
  "modified": "2026-09-23T23:35:43Z",
  "published": "2026-08-19T21:17:00Z",
  "references": [
    {
      "type": "REPORT",
      "url": "https://ubuntu.com/security/CVE-2026-75595"
    },
    {
      "type": "REPORT",
      "url": "https://www.cve.org/CVERecord?id=CVE-2026-75595"
    },
    {
      "type": "REPORT",
      "url": "https://github.com/netty/netty/security/advisories/GHSA-fccg-mwvh-qqg4"
    },
    {
      "type": "REPORT",
      "url": "https://github.com/netty/netty/pull/17213"
    },
    {
      "type": "REPORT",
      "url": "https://github.com/netty/netty/pull/17217"
    },
    {
      "type": "REPORT",
      "url": "https://github.com/netty/netty/commit/1b5abc6443b63726c72cdd285af2feb7ddbb8ff7"
    },
    {
      "type": "REPORT",
      "url": "https://github.com/netty/netty/commit/9e0519239108a69b7e9bbc5e9182ee139a0d7961"
    },
    {
      "type": "REPORT",
      "url": "https://github.com/netty/netty/releases/tag/netty-4.1.137.Final"
    },
    {
      "type": "REPORT",
      "url": "https://github.com/netty/netty/releases/tag/netty-4.2.17.Final"
    },
    {
      "type": "REPORT",
      "url": "https://github.com/netty/netty/security/advisories/GHSA-c4c3-7fpv-j4q5"
    }
  ],
  "related": [],
  "schema_version": "1.7.0",
  "severity": [
    {
      "score": "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N",
      "type": "CVSS_V4"
    },
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N",
      "type": "CVSS_V3"
    },
    {
      "score": "medium",
      "type": "Ubuntu"
    }
  ],
  "upstream": [
    "CVE-2026-75595"
  ]
}



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