{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-52920", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-06-09T07:44:35.367Z", "datePublished": "2026-06-24T07:14:15.866Z", "dateUpdated": "2026-08-05T12:31:42.384Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T12:31:42.384Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnetfilter: xt_policy: fix strict mode inbound policy matching\n\nmatch_policy_in() walks sec_path entries from the last transform to the\nfirst one, but strict policy matching needs to consume info->pol[] in\nthe same forward order as the rule layout.\n\nDerive the strict-match policy position from the number of transforms\nalready consumed so that multi-element inbound rules are matched\nconsistently." } ], "metrics": [ { "cvssV3_1": { "version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:H", "baseScore": 8.3, "baseSeverity": "HIGH" }, "scenarios": [ { "lang": "en", "value": "AV:N - The vulnerable matcher is executed while processing inbound IPv4/IPv6 packets through x_tables after XFRM/IPsec has populated the packet sec_path. A remote IPsec peer can trigger the affected strict inbound policy rule by sending network packets in a realistic VPN/gateway deployment.\nAC:L - Exploitation requires a strict inbound xt_policy rule with multiple policy elements and a packet with the same number of transforms, but those are normal affected configurations rather than attacker-uncontrolled races. Once present, triggering is repeatable by sending matching packets.\nPR:L - Unauthenticated packets generally fail XFRM state/authentication before reaching this sec_path-based match, so the network scenario requires an authorized IPsec peer or equivalent low privilege. Locally, the rule/XFRM setup is gated by CAP_NET_ADMIN in the network namespace, which is reachable through user namespaces.\nUI:N - No victim user action is needed after the vulnerable rule/state configuration exists. Packet delivery or local namespace traffic is sufficient to invoke the matcher.\nS:U - The bug is in kernel netfilter/XFRM policy evaluation and impacts the same kernel/network security authority. It does not cross a VM, IOMMU, or separate sandbox security scope.\nC:H - The old strict inbound index calculation can make pos negative and read before info->pol[], including x_tables rule metadata or adjacent kernel allocation contents. Although exposed through match behavior rather than a direct copy_to_user, this is an out-of-bounds kernel read larger than a few bytes, so the higher confidentiality impact is warranted.\nI:L - The bug does not provide a direct write primitive or code execution path, but it can make strict IPsec policy matching produce incorrect firewall decisions. That can bypass or misapply intended packet filtering for affected multi-element inbound rules.\nA:H - The negative-index read can reach outside the intended match data and, for larger strict transform counts or unlucky layout, may fault/oops in kernel packet processing. The condition can be triggered repeatedly with packets once the affected rule path is reachable." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "net/netfilter/xt_policy.c" ], "versions": [ { "version": "c4b885139203d37f76662c37ae645fe8e0f4e4e5", "lessThan": "eb323f7b82d2e2f638de0cc2a177803eb20e0707", "status": "affected", "versionType": "git" }, { "version": "c4b885139203d37f76662c37ae645fe8e0f4e4e5", "lessThan": "fc1c518bb1f054831ecabb32da9b8e1dff9699c6", "status": "affected", "versionType": "git" }, { "version": "c4b885139203d37f76662c37ae645fe8e0f4e4e5", "lessThan": "f98b7f85e04b40e28b08c461ded0cc79f14f5509", "status": "affected", "versionType": "git" }, { "version": "c4b885139203d37f76662c37ae645fe8e0f4e4e5", "lessThan": "82664d0f1ba25e4f9a71994954abae24c60f4067", "status": "affected", "versionType": "git" }, { "version": "c4b885139203d37f76662c37ae645fe8e0f4e4e5", "lessThan": "b130a6eefa02bd4d475f2f059da8bcfb3e7d18d9", "status": "affected", "versionType": "git" }, { "version": "c4b885139203d37f76662c37ae645fe8e0f4e4e5", "lessThan": "938867e870fb5471bb16f442aeac81326e05bf65", "status": "affected", "versionType": "git" }, { "version": "c4b885139203d37f76662c37ae645fe8e0f4e4e5", "lessThan": "392cc1d8408b5665215c1e9290bbf0f92339b043", "status": "affected", "versionType": "git" }, { "version": "c4b885139203d37f76662c37ae645fe8e0f4e4e5", "lessThan": "4b2b4d7d4e203c92db8966b163edfacb1f0e1e29", "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/xt_policy.c" ], "versions": [ { "version": "2.6.17", "status": "affected" }, { "version": "0", "lessThan": "2.6.17", "status": "unaffected", "versionType": "semver" }, { "version": "5.10.258", "lessThanOrEqual": "5.10.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.15.209", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.175", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.141", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.91", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.33", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.0.10", "lessThanOrEqual": "7.0.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.1", "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": "2.6.17", "versionEndExcluding": "5.10.258" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.17", "versionEndExcluding": "5.15.209" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.17", "versionEndExcluding": "6.1.175" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.17", "versionEndExcluding": "6.6.141" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.17", "versionEndExcluding": "6.12.91" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.17", "versionEndExcluding": "6.18.33" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.17", "versionEndExcluding": "7.0.10" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.17", "versionEndExcluding": "7.1" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/eb323f7b82d2e2f638de0cc2a177803eb20e0707" }, { "url": "https://git.kernel.org/stable/c/fc1c518bb1f054831ecabb32da9b8e1dff9699c6" }, { "url": "https://git.kernel.org/stable/c/f98b7f85e04b40e28b08c461ded0cc79f14f5509" }, { "url": "https://git.kernel.org/stable/c/82664d0f1ba25e4f9a71994954abae24c60f4067" }, { "url": "https://git.kernel.org/stable/c/b130a6eefa02bd4d475f2f059da8bcfb3e7d18d9" }, { "url": "https://git.kernel.org/stable/c/938867e870fb5471bb16f442aeac81326e05bf65" }, { "url": "https://git.kernel.org/stable/c/392cc1d8408b5665215c1e9290bbf0f92339b043" }, { "url": "https://git.kernel.org/stable/c/4b2b4d7d4e203c92db8966b163edfacb1f0e1e29" } ], "title": "netfilter: xt_policy: fix strict mode inbound policy matching", "x_generator": { "engine": "bippy-1.2.0" } } } }