{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-23457", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-01-13T15:37:46.020Z", "datePublished": "2026-04-03T15:15:38.193Z", "dateUpdated": "2026-08-05T12:21:56.236Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T12:21:56.236Z" }, "descriptions": [ { "lang": "en", "value": "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." } ], "metrics": [ { "cvssV3_1": { "version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:H", "baseScore": 8.6, "baseSeverity": "HIGH" }, "scenarios": [ { "lang": "en", "value": "AV:N - The vulnerable parser is reached by TCP SIP packets processed by the in-kernel netfilter SIP conntrack helper on a firewall/NAT/SIP gateway. In a reasonable SIP ALG deployment, a remote peer can deliver the crafted SIP payload over the network.\nAC:L - The attacker controls the SIP TCP stream contents, including the oversized Content-Length and trailing data that is reinterpreted as another SIP/SDP message. No race or condition outside the attacker's control is required once the helper is active.\nPR:N - A remote SIP peer does not need local credentials or kernel privileges to send packets through an already configured SIP conntrack helper. Although local CAP_NET_ADMIN can configure helpers, the highest reasonable deployment is a network-facing SIP gateway where the attacker only sends traffic.\nUI:N - No victim user action is needed after the SIP helper is deployed. The crafted TCP payload is processed automatically on packet traversal.\nS:U - The affected logic is kernel netfilter conntrack/NAT state within the same security authority. This is not a VM escape, IOMMU bypass, or other cross-scope boundary break.\nC:L - The bug does not expose kernel memory, but smuggled SDP can create unintended SIP media expectations that may allow limited otherwise-blocked traffic to protected endpoints. That can expose limited traffic or service responses behind the firewall.\nI:L - The primary impact is limited integrity loss in conntrack/NAT policy state: attacker-controlled trailing bytes can be processed as a separate SIP/SDP message and create or alter expectations. This is not arbitrary kernel memory write or code execution.\nA:H - Crafted traffic can repeatedly drive incorrect SIP helper parsing, packet drops, NAT mangling, and expectation-state pollution for affected SIP flows. In a SIP gateway scenario this can deny call or media setup through the affected subsystem." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "net/netfilter/nf_conntrack_sip.c" ], "versions": [ { "version": "f5b321bd37fbec9188feb1f721ab46a5ac0b35da", "lessThan": "ed81b6a7012485acdb9c6c80735a0b7d8e5e1873", "status": "affected", "versionType": "git" }, { "version": "f5b321bd37fbec9188feb1f721ab46a5ac0b35da", "lessThan": "cd1b7403ec835f8a0b3f1f7e68ac26af2cb1e42f", "status": "affected", "versionType": "git" }, { "version": "f5b321bd37fbec9188feb1f721ab46a5ac0b35da", "lessThan": "b75209debb9adab287b3caa982f77788c1e15027", "status": "affected", "versionType": "git" }, { "version": "f5b321bd37fbec9188feb1f721ab46a5ac0b35da", "lessThan": "528b4509c9dfc272e2e92d811915e5211650d383", "status": "affected", "versionType": "git" }, { "version": "f5b321bd37fbec9188feb1f721ab46a5ac0b35da", "lessThan": "75fcaee5170e7dbbee778927134ef2e9568b4659", "status": "affected", "versionType": "git" }, { "version": "f5b321bd37fbec9188feb1f721ab46a5ac0b35da", "lessThan": "865dba58958c3a86786f89a501971ab0e3ec6ba9", "status": "affected", "versionType": "git" }, { "version": "f5b321bd37fbec9188feb1f721ab46a5ac0b35da", "lessThan": "d4f17256544cc37f6534a14a27a9dec3540c2015", "status": "affected", "versionType": "git" }, { "version": "f5b321bd37fbec9188feb1f721ab46a5ac0b35da", "lessThan": "fbce58e719a17aa215c724473fd5baaa4a8dc57c", "status": "affected", "versionType": "git" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "net/netfilter/nf_conntrack_sip.c" ], "versions": [ { "version": "2.6.34", "status": "affected" }, { "version": "0", "lessThan": "2.6.34", "status": "unaffected", "versionType": "semver" }, { "version": "5.10.253", "lessThanOrEqual": "5.10.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.15.203", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.167", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.130", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.78", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.20", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.19.10", "lessThanOrEqual": "6.19.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.0", "lessThanOrEqual": "*", "status": "unaffected", "versionType": "original_commit_for_fix" } ] } ], "cpeApplicability": [ { "nodes": [ { "operator": "OR", "negate": false, "cpeMatch": [ { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.34", "versionEndExcluding": "5.10.253" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.34", "versionEndExcluding": "5.15.203" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.34", "versionEndExcluding": "6.1.167" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.34", "versionEndExcluding": "6.6.130" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.34", "versionEndExcluding": "6.12.78" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.34", "versionEndExcluding": "6.18.20" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.34", "versionEndExcluding": "6.19.10" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.34", "versionEndExcluding": "7.0" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/ed81b6a7012485acdb9c6c80735a0b7d8e5e1873" }, { "url": "https://git.kernel.org/stable/c/cd1b7403ec835f8a0b3f1f7e68ac26af2cb1e42f" }, { "url": "https://git.kernel.org/stable/c/b75209debb9adab287b3caa982f77788c1e15027" }, { "url": "https://git.kernel.org/stable/c/528b4509c9dfc272e2e92d811915e5211650d383" }, { "url": "https://git.kernel.org/stable/c/75fcaee5170e7dbbee778927134ef2e9568b4659" }, { "url": "https://git.kernel.org/stable/c/865dba58958c3a86786f89a501971ab0e3ec6ba9" }, { "url": "https://git.kernel.org/stable/c/d4f17256544cc37f6534a14a27a9dec3540c2015" }, { "url": "https://git.kernel.org/stable/c/fbce58e719a17aa215c724473fd5baaa4a8dc57c" } ], "title": "netfilter: nf_conntrack_sip: fix Content-Length u32 truncation in sip_help_tcp()", "x_generator": { "engine": "bippy-1.2.0" } }, "adp": [ { "x_adpType": "supplier", "providerMetadata": { "orgId": "0b142b55-0307-4c5a-b3c9-f314f3fb7c5e", "shortName": "siemens-SADP", "dateUpdated": "2026-07-14T12:47:15.162Z" }, "affected": [ { "vendor": "Siemens", "product": "SIMATIC S7-1500 CPU 1518-4 PN/DP MFP", "versions": [ { "status": "affected", "version": "V3.1.6", "lessThan": "*", "versionType": "custom" } ], "defaultStatus": "unknown" }, { "vendor": "Siemens", "product": "SIMATIC S7-1500 CPU 1518-4 PN/DP MFP", "versions": [ { "status": "affected", "version": "V3.1.5", "lessThan": "*", "versionType": "custom" } ], "defaultStatus": "unknown" }, { "vendor": "Siemens", "product": "SIMATIC S7-1500 CPU 1518-4 PN/DP MFP", "versions": [ { "status": "affected", "version": "V3.1.6", "lessThan": "*", "versionType": "custom" } ], "defaultStatus": "unknown" }, { "vendor": "Siemens", "product": "SIMATIC S7-1500 CPU 1518-4 PN/DP MFP", "versions": [ { "status": "affected", "version": "V3.1.5", "lessThan": "*", 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