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netfilter: nf_conntrack_sip: fix Content-Length u32 truncation in sip_help_tcp()

Type: advisorySource: Official CVE List1 source record

In the Linux kernel, the following vulnerability has been resolved: netfilter: nf_conntrack_sip: fix Content-Length u32 truncation in sip_help_tcp() sip_help_tcp() parses the SIP Content-Length header with simple_strtoul(), which returns unsigned long, but stores the result in unsigned int clen. On 64-bit systems, values exceeding UINT_MAX are silently truncated before computing the SIP message boundary. For example, Content-Length 4294967328 (2^32 + 32) is truncated to 32, causing the parser to miscalculate where the current message ends. The loop then treats trailing data in the TCP segment as a second SIP message and processes it through the SDP parser. Fix this by changing clen to unsigned long to match the return type of simple_strtoul(), and reject Content-Length values that exceed the remaining TCP payload length.

Announced Source revision 1
Original source ↗

CVE-2026-23457

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-2026-23457

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": "f5b321bd37fbec9188feb1f721ab46a5ac0b35da",
        "lessThan": "ed81b6a7012485acdb9c6c80735a0b7d8e5e1873",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "f5b321bd37fbec9188feb1f721ab46a5ac0b35da",
        "lessThan": "cd1b7403ec835f8a0b3f1f7e68ac26af2cb1e42f",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "f5b321bd37fbec9188feb1f721ab46a5ac0b35da",
        "lessThan": "b75209debb9adab287b3caa982f77788c1e15027",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "f5b321bd37fbec9188feb1f721ab46a5ac0b35da",
        "lessThan": "528b4509c9dfc272e2e92d811915e5211650d383",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "f5b321bd37fbec9188feb1f721ab46a5ac0b35da",
        "lessThan": "75fcaee5170e7dbbee778927134ef2e9568b4659",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "f5b321bd37fbec9188feb1f721ab46a5ac0b35da",
        "lessThan": "865dba58958c3a86786f89a501971ab0e3ec6ba9",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "f5b321bd37fbec9188feb1f721ab46a5ac0b35da",
        "lessThan": "d4f17256544cc37f6534a14a27a9dec3540c2015",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "f5b321bd37fbec9188feb1f721ab46a5ac0b35da",
        "lessThan": "fbce58e719a17aa215c724473fd5baaa4a8dc57c",
        "versionType": "git"
      }
    ],
    "programFiles": [
      "net/netfilter/nf_conntrack_sip.c"
    ],
    "defaultStatus": "unaffected"
  },
  {
    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
    "vendor": "Linux",
    "product": "Linux",
    "versions": [
      {
        "status": "affected",
        "version": "2.6.34"
      },
      {
        "status": "unaffected",
        "version": "0",
        "lessThan": "2.6.34",
        "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_sip.c"
    ],
    "defaultStatus": "affected"
  }
]
Related CVEs
CVE-2026-23457

Source reference: /cveMetadata/cveId

Publisher severity

high

Source reference: /containers/cna/metrics

Event
#39857 · Revision 1
Added to Heist Feed
Publisher date
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