{ "cvss": 5.5, "datePublished": "2026-04-22T14:16:47.500", "dateUpdated": "2026-11-05T22:18:34.970", "description": "In the Linux kernel, the following vulnerability has been resolved:\n\nnetfilter: ctnetlink: use netlink policy range checks\n\nReplace manual range and mask validations with netlink policy\nannotations in ctnetlink code paths, so that the netlink core rejects\ninvalid values early and can generate extack errors.\n\n- CTA_PROTOINFO_TCP_STATE: reject values > TCP_CONNTRACK_SYN_SENT2 at\n policy level, removing the manual >= TCP_CONNTRACK_MAX check.\n- CTA_PROTOINFO_TCP_WSCALE_ORIGINAL/REPLY: reject values > TCP_MAX_WSCALE\n (14). The normal TCP option parsing path already clamps to this value,\n but the ctnetlink path accepted 0-255, causing undefined behavior when\n used as a u32 shift count.\n- CTA_FILTER_ORIG_FLAGS/REPLY_FLAGS: use NLA_POLICY_MASK with\n CTA_FILTER_F_ALL, removing the manual mask checks.\n- CTA_EXPECT_FLAGS: use NLA_POLICY_MASK with NF_CT_EXPECT_MASK, adding\n a new mask define grouping all valid expect flags.\n\nExtracted from a broader nf-next patch by Florian Westphal, scoped to\nctnetlink for the fixes tree.", "id": "CVE-2026-31495", "raw": { "affected": [ { "affectedData": [ { "defaultStatus": "unaffected", "product": "Linux", "programFiles": [ "include/uapi/linux/netfilter/nf_conntrack_common.h", "net/netfilter/nf_conntrack_netlink.c", "net/netfilter/nf_conntrack_proto_tcp.c" ], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [ { "lessThan": "435b576cd2faa75154777868f8cbb73bf71644d3", "status": "affected", "version": "c8e2078cfe414a99cf6f2f2f1d78c7e75392e9d4", "versionType": "git" }, { "lessThan": "2ef71307c86a9f866d6e28f1a0c06e2e9d794474", "status": "affected", "version": "c8e2078cfe414a99cf6f2f2f1d78c7e75392e9d4", "versionType": "git" }, { "lessThan": "4f7d25f3f0786402ba48ff7d13b6241d77d975f5", "status": "affected", "version": "c8e2078cfe414a99cf6f2f2f1d78c7e75392e9d4", "versionType": "git" }, { "lessThan": "fcec5ce2d73a41668b24e3f18c803541602a59f6", "status": "affected", "version": "c8e2078cfe414a99cf6f2f2f1d78c7e75392e9d4", "versionType": "git" }, { "lessThan": "675c913b940488a84effdeeac5a1cfb657b59804", "status": "affected", "version": "c8e2078cfe414a99cf6f2f2f1d78c7e75392e9d4", "versionType": "git" }, { "lessThan": "c6cb41eaae875501eaaa487b8db6539feb092292", "status": "affected", "version": "c8e2078cfe414a99cf6f2f2f1d78c7e75392e9d4", "versionType": "git" }, { "lessThan": "45c33e79ae705b7af97e3117672b6cd258dd0b1b", "status": "affected", "version": "c8e2078cfe414a99cf6f2f2f1d78c7e75392e9d4", "versionType": "git" }, { "lessThan": "8f15b5071b4548b0aafc03b366eb45c9c6566704", "status": "affected", "version": "c8e2078cfe414a99cf6f2f2f1d78c7e75392e9d4", "versionType": "git" } ] }, { "defaultStatus": "affected", "product": "Linux", "programFiles": [ "include/uapi/linux/netfilter/nf_conntrack_common.h", "net/netfilter/nf_conntrack_netlink.c", "net/netfilter/nf_conntrack_proto_tcp.c" ], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [ { "status": "affected", "version": "2.6.22" }, { "lessThan": "2.6.22", "status": "unaffected", "version": "0", "versionType": "semver" }, { "lessThanOrEqual": "5.10.*", "status": "unaffected", "version": "5.10.253", "versionType": "semver" }, { "lessThanOrEqual": "5.15.*", "status": "unaffected", "version": "5.15.203", "versionType": "semver" }, { "lessThanOrEqual": "6.1.*", "status": "unaffected", "version": "6.1.168", "versionType": "semver" }, { "lessThanOrEqual": "6.6.*", "status": "unaffected", "version": "6.6.131", "versionType": "semver" }, { "lessThanOrEqual": "6.12.*", "status": "unaffected", "version": "6.12.80", "versionType": "semver" }, { "lessThanOrEqual": "6.18.*", "status": "unaffected", "version": "6.18.21", "versionType": "semver" }, { "lessThanOrEqual": "6.19.*", "status": "unaffected", "version": "6.19.11", "versionType": "semver" }, { "lessThanOrEqual": "*", "status": "unaffected", "version": "7.0", "versionType": "original_commit_for_fix" } ] } ], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67" }, { "affectedData": [ { "defaultStatus": "unknown", "product": "SIMATIC S7-1500 CPU 1518-4 PN/DP MFP", "vendor": "Siemens", "versions": [ { "lessThan": "*", "status": "affected", "version": "V3.1.6", "versionType": "custom" } ] }, { "defaultStatus": "unknown", "product": "SIMATIC S7-1500 CPU 1518-4 PN/DP MFP", "vendor": "Siemens", "versions": [ { "lessThan": "*", "status": "affected", "version": "V3.1.5", "versionType": "custom" } ] }, { "defaultStatus": "unknown", "product": "SIMATIC S7-1500 CPU 1518-4 PN/DP MFP", "vendor": "Siemens", "versions": [ { "lessThan": "*", "status": "affected", "version": "V3.1.7", "versionType": "custom" } ] }, { "defaultStatus": "unknown", "product": "SIMATIC S7-1500 CPU 1518-4 PN/DP MFP", "vendor": "Siemens", "versions": [ { "lessThan": "*", "status": "affected", "version": "V3.1.6", "versionType": "custom" } ] }, { "defaultStatus": "unknown", "product": "SIMATIC S7-1500 CPU 1518-4 PN/DP MFP", "vendor": "Siemens", "versions": [ { "lessThan": "*", "status": "affected", "version": "V3.1.5", "versionType": "custom" } ] }, { "defaultStatus": "unknown", "product": "SIMATIC S7-1500 CPU 1518-4 PN/DP MFP", "vendor": "Siemens", "versions": [ { "lessThan": "*", "status": "affected", "version": "V3.1.7", "versionType": "custom" } ] }, { "defaultStatus": "unknown", "product": "SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP", "vendor": "Siemens", "versions": [ { "lessThan": "*", "status": "affected", "version": "V3.1.6", "versionType": "custom" } ] }, { "defaultStatus": "unknown", "product": "SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP", "vendor": "Siemens", "versions": [ { "lessThan": "*", "status": "affected", "version": "V3.1.5", "versionType": "custom" } ] }, { "defaultStatus": "unknown", "product": "SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP", "vendor": "Siemens", "versions": [ { "lessThan": "*", "status": "affected", "version": "V3.1.7", "versionType": "custom" } ] }, { "defaultStatus": "unknown", "product": "SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP", "vendor": "Siemens", "versions": [ { "lessThan": "*", "status": "affected", "version": "V3.1.6", "versionType": "custom" } ] }, { "defaultStatus": "unknown", "product": "SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP", "vendor": "Siemens", "versions": [ { "lessThan": "*", "status": "affected", "version": "V3.1.5", "versionType": "custom" } ] }, { "defaultStatus": "unknown", "product": "SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP", "vendor": "Siemens", "versions": [ { "lessThan": "*", "status": "affected", "version": "V3.1.7", "versionType": "custom" } ] }, { "defaultStatus": "unknown", "product": "SIPLUS S7-1500 CPU 1518-4 PN/DP MFP", "vendor": "Siemens", "versions": [ { "lessThan": "*", "status": "affected", "version": "V3.1.6", "versionType": "custom" } ] }, { "defaultStatus": "unknown", "product": "SIPLUS S7-1500 CPU 1518-4 PN/DP MFP", "vendor": "Siemens", "versions": [ { "lessThan": "*", "status": "affected", "version": "V3.1.5", "versionType": "custom" } ] }, { "defaultStatus": "unknown", "product": "SIPLUS S7-1500 CPU 1518-4 PN/DP MFP", "vendor": "Siemens", "versions": [ { "lessThan": "*", "status": "affected", "version": "V3.1.7", "versionType": "custom" } ] } ], "source": "0b142b55-0307-4c5a-b3c9-f314f3fb7c5e" } ], "configurations": [ { "nodes": [ { "cpeMatch": [ { "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "matchCriteriaId": "E7333FD1-B48C-4F9D-BF44-8273A10F72A2", "versionEndExcluding": "5.10.253", "versionStartIncluding": "2.6.22.1", "vulnerable": true }, { "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "matchCriteriaId": "20DDB3E9-AABF-4107-ADB0-5362AA067045", "versionEndExcluding": "5.15.203", "versionStartIncluding": "5.11", "vulnerable": true }, { "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "matchCriteriaId": "E2DDDCA1-6DAB-4018-B920-8F045DDD8D3B", "versionEndExcluding": "6.1.168", "versionStartIncluding": "5.16", "vulnerable": true }, { "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "matchCriteriaId": "CE6ED4D4-0046-4573-BFA9-D64143B6A89F", "versionEndExcluding": "6.6.131", "versionStartIncluding": "6.2", "vulnerable": true }, { "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "matchCriteriaId": "97EB19EC-A11E-49C6-9D2F-6F6EC6CB98B6", "versionEndExcluding": "6.12.80", "versionStartIncluding": "6.7", "vulnerable": true }, { "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "matchCriteriaId": "ED39847A-3B46-4729-B7CA-B2C30B9FA8FE", "versionEndExcluding": "6.18.21", "versionStartIncluding": "6.13", "vulnerable": true }, { "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "matchCriteriaId": "4CA2E747-A9EC-4518-9AA2-B4247FC748B7", "versionEndExcluding": "6.19.11", "versionStartIncluding": "6.19", "vulnerable": true }, { "criteria": "cpe:2.3:o:linux:linux_kernel:2.6.22:-:*:*:*:*:*:*", "matchCriteriaId": "7F7D6C66-3384-4ACC-9D08-C5A26B4FD004", "vulnerable": true }, { "criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc1:*:*:*:*:*:*", "matchCriteriaId": "F253B622-8837-4245-BCE5-A7BF8FC76A16", "vulnerable": true }, { "criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc2:*:*:*:*:*:*", "matchCriteriaId": "4AE85AD8-4641-4E7C-A2F4-305E2CD9EE64", "vulnerable": true }, { "criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc3:*:*:*:*:*:*", "matchCriteriaId": "F666C8D8-6538-46D4-B318-87610DE64C34", "vulnerable": true }, { "criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc4:*:*:*:*:*:*", "matchCriteriaId": "02259FDA-961B-47BC-AE7F-93D7EC6E90C2", "vulnerable": true }, { "criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc5:*:*:*:*:*:*", "matchCriteriaId": "58A9FEFF-C040-420D-8F0A-BFDAAA1DF258", "vulnerable": true }, { "criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc6:*:*:*:*:*:*", "matchCriteriaId": "1D2315C0-D46F-4F85-9754-F9E5E11374A6", "vulnerable": true }, { "criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc7:*:*:*:*:*:*", "matchCriteriaId": "512EE3A8-A590-4501-9A94-5D4B268D6138", "vulnerable": true } ], "negate": false, "operator": "OR" } ] } ], "cveTags": [], "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnetfilter: ctnetlink: use netlink policy range checks\n\nReplace manual range and mask validations with netlink policy\nannotations in ctnetlink code paths, so that the netlink core rejects\ninvalid values early and can generate extack errors.\n\n- CTA_PROTOINFO_TCP_STATE: reject values > TCP_CONNTRACK_SYN_SENT2 at\n policy level, removing the manual >= TCP_CONNTRACK_MAX check.\n- CTA_PROTOINFO_TCP_WSCALE_ORIGINAL/REPLY: reject values > TCP_MAX_WSCALE\n (14). The normal TCP option parsing path already clamps to this value,\n but the ctnetlink path accepted 0-255, causing undefined behavior when\n used as a u32 shift count.\n- CTA_FILTER_ORIG_FLAGS/REPLY_FLAGS: use NLA_POLICY_MASK with\n CTA_FILTER_F_ALL, removing the manual mask checks.\n- CTA_EXPECT_FLAGS: use NLA_POLICY_MASK with NF_CT_EXPECT_MASK, adding\n a new mask define grouping all valid expect flags.\n\nExtracted from a broader nf-next patch by Florian Westphal, scoped to\nctnetlink for the fixes tree." } ], "id": "CVE-2026-31495", "lastModified": "2026-11-05T22:18:34.970", "metrics": { "cvssMetricV31": [ { "cvssData": { "attackComplexity": "LOW", "attackVector": "LOCAL", "availabilityImpact": "HIGH", "baseScore": 5.5, "baseSeverity": "MEDIUM", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "privilegesRequired": "LOW", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H", "version": "3.1" }, "exploitabilityScore": 1.8, "impactScore": 3.6, "source": "nvd@nist.gov", "type": "Primary" } ], "ssvcV203": [ { "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": { "id": "CVE-2026-31495", "options": [ { "exploitation": "none" }, { "automatable": "no" }, { "technicalImpact": "partial" } ], "role": "CISA Coordinator", "timestamp": "2026-11-05T21:35:22.554497Z", "version": "2.0.3" } } ] }, "published": "2026-04-22T14:16:47.500", "references": [ { "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": [ "Patch" ], "url": "https://git.kernel.org/stable/c/2ef71307c86a9f866d6e28f1a0c06e2e9d794474" }, { "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": [ "Patch" ], "url": "https://git.kernel.org/stable/c/435b576cd2faa75154777868f8cbb73bf71644d3" }, { "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": [ "Patch" ], "url": "https://git.kernel.org/stable/c/45c33e79ae705b7af97e3117672b6cd258dd0b1b" }, { "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": [ "Patch" ], "url": "https://git.kernel.org/stable/c/4f7d25f3f0786402ba48ff7d13b6241d77d975f5" }, { "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": [ "Patch" ], "url": "https://git.kernel.org/stable/c/675c913b940488a84effdeeac5a1cfb657b59804" }, { "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": [ "Patch" ], "url": "https://git.kernel.org/stable/c/8f15b5071b4548b0aafc03b366eb45c9c6566704" }, { "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": [ "Patch" ], "url": "https://git.kernel.org/stable/c/c6cb41eaae875501eaaa487b8db6539feb092292" }, { "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": [ "Patch" ], "url": "https://git.kernel.org/stable/c/fcec5ce2d73a41668b24e3f18c803541602a59f6" }, { "source": "0b142b55-0307-4c5a-b3c9-f314f3fb7c5e", "url": "https://cert-portal.siemens.com/productcert/html/ssa-019113.html" }, { "source": "0b142b55-0307-4c5a-b3c9-f314f3fb7c5e", "url": "https://cert-portal.siemens.com/productcert/html/ssa-082556.html" }, { "source": "0b142b55-0307-4c5a-b3c9-f314f3fb7c5e", "url": "https://cert-portal.siemens.com/productcert/html/ssa-457936.html" } ], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "vulnStatus": "Modified", "weaknesses": [ { "description": [ { "lang": "en", "value": "NVD-CWE-noinfo" } ], "source": "nvd@nist.gov", "type": "Primary" } ] }, "severity": "MEDIUM", "source": "nvd", "title": "In the Linux kernel, the following vulnerability has been resolved:\n\nnetfilter: ctnetlink: use netlink policy range c..." }