netfilter: nf_conntrack_sip: fix Content-Length u32 truncation in sip_help_tcp()_CVE-2026-23457

{
    "lastseen": "",
    "description": "In the Linux kernel, the following vulnerability has been resolved:\n\nnetfilter: nf_conntrack_sip: fix Content-Length u32 truncation in sip_help_tcp()\n\nsip_help_tcp() parses the SIP Content-Length header with\nsimple_strtoul(), which returns unsigned long, but stores the result in\nunsigned int clen.  On 64-bit systems, values exceeding UINT_MAX are\nsilently truncated before computing the SIP message boundary.\n\nFor example, Content-Length 4294967328 (2^32 + 32) is truncated to 32,\ncausing the parser to miscalculate where the current message ends.  The\nloop then treats trailing data in the TCP segment as a second SIP\nmessage and processes it through the SDP parser.\n\nFix this by changing clen to unsigned long to match the return type of\nsimple_strtoul(), and reject Content-Length values that exceed the\nremaining TCP payload length.",
    "published": "2026-04-03T15:15:38.193Z",
    "modified": "2026-04-27T14:02:35.826Z",
    "type": "cve",
    "title": "netfilter: nf_conntrack_sip: fix Content-Length u32 truncation in sip_help_tcp()",
    "source": "Linux",
    "references": "https://git.kernel.org/stable/c/ed81b6a7012485acdb9c6c80735a0b7d8e5e1873\nhttps://git.kernel.org/stable/c/cd1b7403ec835f8a0b3f1f7e68ac26af2cb1e42f\nhttps://git.kernel.org/stable/c/b75209debb9adab287b3caa982f77788c1e15027\nhttps://git.kernel.org/stable/c/528b4509c9dfc272e2e92d811915e5211650d383\nhttps://git.kernel.org/stable/c/75fcaee5170e7dbbee778927134ef2e9568b4659\nhttps://git.kernel.org/stable/c/865dba58958c3a86786f89a501971ab0e3ec6ba9\nhttps://git.kernel.org/stable/c/d4f17256544cc37f6534a14a27a9dec3540c2015\nhttps://git.kernel.org/stable/c/fbce58e719a17aa215c724473fd5baaa4a8dc57c",
    "id": "CVE-2026-23457",
    "bulletinFamily": "",
    "cwe": null,
    "cvelist": null,
    "sourceData": "Linux Linux f5b321bd37fbec9188feb1f721ab46a5ac0b35da\nLinux Linux f5b321bd37fbec9188feb1f721ab46a5ac0b35da\nLinux Linux f5b321bd37fbec9188feb1f721ab46a5ac0b35da\nLinux Linux f5b321bd37fbec9188feb1f721ab46a5ac0b35da\nLinux Linux f5b321bd37fbec9188feb1f721ab46a5ac0b35da\nLinux Linux f5b321bd37fbec9188feb1f721ab46a5ac0b35da\nLinux Linux f5b321bd37fbec9188feb1f721ab46a5ac0b35da\nLinux Linux f5b321bd37fbec9188feb1f721ab46a5ac0b35da\nLinux Linux 2.6.34",
    "sourceHref": "",
    "cvss": {
        "score": 8.6,
        "severity": "HIGH",
        "vector": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:H",
        "version": "3.1"
    },
    "cvss2": [],
    "cvss3": {
        "version": "",
        "vectorString": "",
        "baseScore": 0,
        "baseSeverity": "",
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        "attackComplexity": "",
        "privilegesRequired": "",
        "userInteraction": "",
        "scope": "",
        "confidentialityImpact": "",
        "integrityImpact": "",
        "availabilityImpact": "",
        "cvssV3": {
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            "baseScore": 0,
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            "privilegesRequired": "",
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            "confidentialityImpact": "",
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        }
    },
    "href": "",
    "category_name": "CVE",
    "post_link": "",
    "product": "Linux",
    "version": "f5b321bd37fbec9188feb1f721ab46a5ac0b35da",
    "vendor": "Linux",
    "ai_description": "",
    "ai_severity": "",
    "ai_vendor": "",
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    "ai_score": 0
}