CVE-2026-23457 (GCVE-0-2026-23457)

Vulnerability from cvelistv5 – Published: 2026-04-03 15:15 – Updated: 2026-04-27 14:02
VLAI?
Title
netfilter: nf_conntrack_sip: fix Content-Length u32 truncation in sip_help_tcp()
Summary
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.
Severity ?
8.6 (High)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:H
Assigner
References
Impacted products
Vendor Product Version
Linux Linux Affected: f5b321bd37fbec9188feb1f721ab46a5ac0b35da , < ed81b6a7012485acdb9c6c80735a0b7d8e5e1873 (git)
Affected: f5b321bd37fbec9188feb1f721ab46a5ac0b35da , < cd1b7403ec835f8a0b3f1f7e68ac26af2cb1e42f (git)
Affected: f5b321bd37fbec9188feb1f721ab46a5ac0b35da , < b75209debb9adab287b3caa982f77788c1e15027 (git)
Affected: f5b321bd37fbec9188feb1f721ab46a5ac0b35da , < 528b4509c9dfc272e2e92d811915e5211650d383 (git)
Affected: f5b321bd37fbec9188feb1f721ab46a5ac0b35da , < 75fcaee5170e7dbbee778927134ef2e9568b4659 (git)
Affected: f5b321bd37fbec9188feb1f721ab46a5ac0b35da , < 865dba58958c3a86786f89a501971ab0e3ec6ba9 (git)
Affected: f5b321bd37fbec9188feb1f721ab46a5ac0b35da , < d4f17256544cc37f6534a14a27a9dec3540c2015 (git)
Affected: f5b321bd37fbec9188feb1f721ab46a5ac0b35da , < fbce58e719a17aa215c724473fd5baaa4a8dc57c (git)
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    Linux Linux Affected: 2.6.34
Unaffected: 0 , < 2.6.34 (semver)
Unaffected: 5.10.253 , ≤ 5.10.* (semver)
Unaffected: 5.15.203 , ≤ 5.15.* (semver)
Unaffected: 6.1.167 , ≤ 6.1.* (semver)
Unaffected: 6.6.130 , ≤ 6.6.* (semver)
Unaffected: 6.12.78 , ≤ 6.12.* (semver)
Unaffected: 6.18.20 , ≤ 6.18.* (semver)
Unaffected: 6.19.10 , ≤ 6.19.* (semver)
Unaffected: 7.0 , ≤ * (original_commit_for_fix)
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{
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  }
}


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Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

Sightings

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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.