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netfilter: nf_conntrack_h323: check for zero length in DecodeQ931()

Type: advisorySource: Official CVE List1 source record

In the Linux kernel, the following vulnerability has been resolved: netfilter: nf_conntrack_h323: check for zero length in DecodeQ931() In DecodeQ931(), the UserUserIE code path reads a 16-bit length from the packet, then decrements it by 1 to skip the protocol discriminator byte before passing it to DecodeH323_UserInformation(). If the encoded length is 0, the decrement wraps to -1, which is then passed as a large value to the decoder, leading to an out-of-bounds read. Add a check to ensure len is positive after the decrement.

Announced Source revision 1
Original source ↗

CVE-2026-23455

Primary source · Revision 1

Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.

Security context

Source reference: cve:CVE-2026-23455

Linux

Source reference: /containers/cna/affected/0/product

Affected versions
Not stated in this record
Fixed versions
Not stated in this record
Prerequisites
Not stated in this record

Linux

Source reference: /containers/cna/affected/1/product

Affected versions
Not stated in this record
Fixed versions
Not stated in this record
Prerequisites
Not stated in this record

Structured affected-version data

Original package identities and version rules from this source.

[
  {
    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
    "vendor": "Linux",
    "product": "Linux",
    "versions": [
      {
        "status": "affected",
        "version": "5e35941d990123f155b02d5663e51a24f816b6f3",
        "lessThan": "2121f5fbe88daff0f1fc5bc47d359426c74b86b0",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "5e35941d990123f155b02d5663e51a24f816b6f3",
        "lessThan": "65fa92f79677858b14b9e4b7275f26639afe2710",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "5e35941d990123f155b02d5663e51a24f816b6f3",
        "lessThan": "495e97af9e7249ee02b72bb1d0848a6efc3700f4",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "5e35941d990123f155b02d5663e51a24f816b6f3",
        "lessThan": "f5e4f4e4cdb75ec36802059a94195a31f193da60",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "5e35941d990123f155b02d5663e51a24f816b6f3",
        "lessThan": "633e8f87dad32263f6a57dccdb873f042c062111",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "5e35941d990123f155b02d5663e51a24f816b6f3",
        "lessThan": "9d00fe7d6d7c5b5f1065a6e042b54f2e44bd6df8",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "5e35941d990123f155b02d5663e51a24f816b6f3",
        "lessThan": "b652b05d51003ac074b912684f9ec7486231717b",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "5e35941d990123f155b02d5663e51a24f816b6f3",
        "lessThan": "f173d0f4c0f689173f8cdac79991043a4a89bf66",
        "versionType": "git"
      }
    ],
    "programFiles": [
      "net/netfilter/nf_conntrack_h323_asn1.c"
    ],
    "defaultStatus": "unaffected"
  },
  {
    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
    "vendor": "Linux",
    "product": "Linux",
    "versions": [
      {
        "status": "affected",
        "version": "2.6.17"
      },
      {
        "status": "unaffected",
        "version": "0",
        "lessThan": "2.6.17",
        "versionType": "semver"
      },
      {
        "status": "unaffected",
        "version": "5.10.253",
        "versionType": "semver",
        "lessThanOrEqual": "5.10.*"
      },
      {
        "status": "unaffected",
        "version": "5.15.203",
        "versionType": "semver",
        "lessThanOrEqual": "5.15.*"
      },
      {
        "status": "unaffected",
        "version": "6.1.167",
        "versionType": "semver",
        "lessThanOrEqual": "6.1.*"
      },
      {
        "status": "unaffected",
        "version": "6.6.130",
        "versionType": "semver",
        "lessThanOrEqual": "6.6.*"
      },
      {
        "status": "unaffected",
        "version": "6.12.78",
        "versionType": "semver",
        "lessThanOrEqual": "6.12.*"
      },
      {
        "status": "unaffected",
        "version": "6.18.20",
        "versionType": "semver",
        "lessThanOrEqual": "6.18.*"
      },
      {
        "status": "unaffected",
        "version": "6.19.10",
        "versionType": "semver",
        "lessThanOrEqual": "6.19.*"
      },
      {
        "status": "unaffected",
        "version": "7.0",
        "versionType": "original_commit_for_fix",
        "lessThanOrEqual": "*"
      }
    ],
    "programFiles": [
      "net/netfilter/nf_conntrack_h323_asn1.c"
    ],
    "defaultStatus": "affected"
  }
]
Related CVEs
CVE-2026-23455

Source reference: /cveMetadata/cveId

Publisher severity

critical

Source reference: /containers/cna/metrics

Event
#39856 · Revision 1
Added to Heist Feed
Publisher date
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