{
  "affected": [
    {
      "ranges": [
        {
          "events": [
            {
              "introduced": "5e35941d990123f155b02d5663e51a24f816b6f3"
            },
            {
              "fixed": "2121f5fbe88daff0f1fc5bc47d359426c74b86b0"
            },
            {
              "fixed": "65fa92f79677858b14b9e4b7275f26639afe2710"
            },
            {
              "fixed": "495e97af9e7249ee02b72bb1d0848a6efc3700f4"
            },
            {
              "fixed": "f5e4f4e4cdb75ec36802059a94195a31f193da60"
            },
            {
              "fixed": "633e8f87dad32263f6a57dccdb873f042c062111"
            },
            {
              "fixed": "9d00fe7d6d7c5b5f1065a6e042b54f2e44bd6df8"
            },
            {
              "fixed": "b652b05d51003ac074b912684f9ec7486231717b"
            },
            {
              "fixed": "f173d0f4c0f689173f8cdac79991043a4a89bf66"
            }
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "type": "GIT"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "Linux",
        "name": "Kernel"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "2.6.17"
            },
            {
              "fixed": "5.10.253"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "5.11.0"
            },
            {
              "fixed": "5.15.203"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "5.16.0"
            },
            {
              "fixed": "6.1.167"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.2.0"
            },
            {
              "fixed": "6.6.130"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.7.0"
            },
            {
              "fixed": "6.12.78"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.13.0"
            },
            {
              "fixed": "6.18.20"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.19.0"
            },
            {
              "fixed": "6.19.10"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "database_specific": {
    "cna_assigner": "Linux",
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/23xxx/CVE-2026-23455.json"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nnetfilter: nf_conntrack_h323: check for zero length in DecodeQ931()\n\nIn DecodeQ931(), the UserUserIE code path reads a 16-bit length from\nthe packet, then decrements it by 1 to skip the protocol discriminator\nbyte before passing it to DecodeH323_UserInformation(). If the encoded\nlength is 0, the decrement wraps to -1, which is then passed as a\nlarge value to the decoder, leading to an out-of-bounds read.\n\nAdd a check to ensure len is positive after the decrement.",
  "id": "CVE-2026-23455",
  "modified": "2026-07-08T05:36:37.634864091Z",
  "published": "2026-04-03T15:15:36.869Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/2121f5fbe88daff0f1fc5bc47d359426c74b86b0"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/495e97af9e7249ee02b72bb1d0848a6efc3700f4"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/633e8f87dad32263f6a57dccdb873f042c062111"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/65fa92f79677858b14b9e4b7275f26639afe2710"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/9d00fe7d6d7c5b5f1065a6e042b54f2e44bd6df8"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/b652b05d51003ac074b912684f9ec7486231717b"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/f173d0f4c0f689173f8cdac79991043a4a89bf66"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/f5e4f4e4cdb75ec36802059a94195a31f193da60"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/23xxx/CVE-2026-23455.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-23455"
    },
    {
      "type": "PACKAGE",
      "url": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"
    }
  ],
  "schema_version": "1.7.5",
  "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": "netfilter: nf_conntrack_h323: check for zero length in DecodeQ931()"
}