{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-23391", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-01-13T15:37:46.009Z", "datePublished": "2026-03-25T10:33:15.677Z", "dateUpdated": "2026-08-05T12:21:22.123Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T12:21:22.123Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnetfilter: xt_CT: drop pending enqueued packets on template removal\n\nTemplates refer to objects that can go away while packets are sitting in\nnfqueue refer to:\n\n- helper, this can be an issue on module removal.\n- timeout policy, nfnetlink_cttimeout might remove it.\n\nThe use of templates with zone and event cache filter are safe, since\nthis just copies values.\n\nFlush these enqueued packets in case the template rule gets removed." } ], "metrics": [ { "cvssV3_1": { "version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H", "baseScore": 7.8, "baseSeverity": "HIGH" }, "scenarios": [ { "lang": "en", "value": "AV:L - Requires local access to configure iptables rules (CT target with helper/timeout) and NFQUEUE via netlink/setsockopt syscalls. Not remotely exploitable.\nAC:L - The attacker controls both sides of the race — they set up the NFQUEUE and CT rules, send packets to fill the queue, then remove the CT rule to trigger the UAF. No conditions beyond attacker control.\nPR:L - Requires CAP_NET_ADMIN, but ip_tables.c uses ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN), making it reachable from unprivileged user namespaces (unshare -Urn).\nUI:N - No user interaction required. The attacker can set up rules, send packets, and remove rules entirely on their own.\nS:U - Standard kernel privilege escalation within the same security authority. No VM escape, IOMMU bypass, or sandbox escape involved.\nC:H - Use-after-free on the helper/timeout objects allows reading freed and potentially reallocated memory, enabling arbitrary kernel memory disclosure through heap spraying.\nI:H - Use-after-free enables heap spraying — attacker can reclaim the freed helper/timeout object with controlled data, achieving arbitrary write primitives and code execution.\nA:H - Use-after-free reliably causes kernel crashes when the freed helper or timeout object is dereferenced through the dangling template pointer." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "net/netfilter/xt_CT.c" ], "versions": [ { "version": "24de58f465165298aaa8f286b2592f0163706cfe", "lessThan": "55445134d42b84cb0a272e42c98d233ca65eca83", "status": "affected", "versionType": "git" }, { "version": "24de58f465165298aaa8f286b2592f0163706cfe", "lessThan": "cc57506dd66555899560b9c0f24e813f034e12ec", "status": "affected", "versionType": "git" }, { "version": "24de58f465165298aaa8f286b2592f0163706cfe", "lessThan": "d2d0bae0c9a2a17b6990a2966f5cdce0813d6256", "status": "affected", "versionType": "git" }, { "version": "24de58f465165298aaa8f286b2592f0163706cfe", "lessThan": "63b8097cea1923fe82cd598068d0796da8c015ec", "status": "affected", "versionType": "git" }, { "version": "24de58f465165298aaa8f286b2592f0163706cfe", "lessThan": "19a230dec6bb8928e3f96387f9085cf2c79bcef9", "status": "affected", "versionType": "git" }, { "version": "24de58f465165298aaa8f286b2592f0163706cfe", "lessThan": "cb549925875fa06dd155e49db4ac2c5044c30f9c", "status": "affected", "versionType": "git" }, { "version": "24de58f465165298aaa8f286b2592f0163706cfe", "lessThan": "777d02efe3d630cca4c1b63962cec17c57711325", "status": "affected", "versionType": "git" }, { "version": "24de58f465165298aaa8f286b2592f0163706cfe", "lessThan": "f62a218a946b19bb59abdd5361da85fa4606b96b", "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_CT.c" ], "versions": [ { "version": "3.4", "status": "affected" }, { "version": "0", "lessThan": "3.4", "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": "3.4", "versionEndExcluding": "5.10.253" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.4", "versionEndExcluding": "5.15.203" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.4", "versionEndExcluding": "6.1.167" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.4", "versionEndExcluding": "6.6.130" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.4", "versionEndExcluding": "6.12.78" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.4", "versionEndExcluding": "6.18.20" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.4", "versionEndExcluding": "6.19.10" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.4", "versionEndExcluding": "7.0" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/55445134d42b84cb0a272e42c98d233ca65eca83" }, { "url": "https://git.kernel.org/stable/c/cc57506dd66555899560b9c0f24e813f034e12ec" }, { "url": "https://git.kernel.org/stable/c/d2d0bae0c9a2a17b6990a2966f5cdce0813d6256" }, { "url": "https://git.kernel.org/stable/c/63b8097cea1923fe82cd598068d0796da8c015ec" }, { "url": "https://git.kernel.org/stable/c/19a230dec6bb8928e3f96387f9085cf2c79bcef9" }, { "url": "https://git.kernel.org/stable/c/cb549925875fa06dd155e49db4ac2c5044c30f9c" }, { "url": "https://git.kernel.org/stable/c/777d02efe3d630cca4c1b63962cec17c57711325" }, { "url": "https://git.kernel.org/stable/c/f62a218a946b19bb59abdd5361da85fa4606b96b" } ], "title": "netfilter: xt_CT: drop pending enqueued packets on template removal", "x_generator": { "engine": "bippy-1.2.0" } }, "adp": [ { "x_adpType": "supplier", "providerMetadata": { "orgId": "0b142b55-0307-4c5a-b3c9-f314f3fb7c5e", "shortName": "siemens-SADP", "dateUpdated": "2026-07-14T12:46:51.914Z" }, "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": 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