{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-23351", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-01-13T15:37:45.999Z", "datePublished": "2026-03-25T10:27:36.854Z", "dateUpdated": "2026-08-05T12:21:16.780Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T12:21:16.780Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnetfilter: nft_set_pipapo: split gc into unlink and reclaim phase\n\nYiming Qian reports Use-after-free in the pipapo set type:\n Under a large number of expired elements, commit-time GC can run for a very\n long time in a non-preemptible context, triggering soft lockup warnings and\n RCU stall reports (local denial of service).\n\nWe must split GC in an unlink and a reclaim phase.\n\nWe cannot queue elements for freeing until pointers have been swapped.\nExpired elements are still exposed to both the packet path and userspace\ndumpers via the live copy of the data structure.\n\ncall_rcu() does not protect us: dump operations or element lookups starting\nafter call_rcu has fired can still observe the free'd element, unless the\ncommit phase has made enough progress to swap the clone and live pointers\nbefore any new reader has picked up the old version.\n\nThis a similar approach as done recently for the rbtree backend in commit\n35f83a75529a (\"netfilter: nft_set_rbtree: don't gc elements on insert\")." } ], "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 - nftables is accessed via netlink sockets from local system access; it is not reachable directly from the network without local shell access.\nAC:L - The attacker controls both sides: they create nftables sets with expiring elements and trigger commits while sending packets through the rules. The UAF window is wide (between RCU callback completion and pointer swap), making exploitation reliable.\nPR:L - nftables requires CAP_NET_ADMIN, which is obtainable by an unprivileged user via user namespaces (unshare -Urn), as confirmed by netlink_net_capable() checking against the namespace's user_ns.\nUI:N - No user interaction is needed; the attacker creates the nftables rules, elements with expiration, and triggers the commit and packet flow entirely on their own.\nS:U - This is a standard kernel memory corruption vulnerability; it does not cross a security boundary such as a VM or sandbox escape.\nC:H - The use-after-free allows the freed nft_pipapo_elem slab to be reallocated with attacker-controlled content; the packet path reads from the freed structure's nft_set_ext fields, enabling arbitrary kernel memory disclosure.\nI:H - The use-after-free enables heap spraying of the freed element's slab; attacker-controlled data in nft_set_ext offset fields can redirect reads/writes, providing arbitrary write primitives for code execution.\nA:H - The commit message explicitly reports \"soft lockup warnings and RCU stall reports (local denial of service)\" and the UAF itself causes kernel crashes when freed memory is accessed with corrupted contents." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "include/net/netfilter/nf_tables.h", "net/netfilter/nf_tables_api.c", "net/netfilter/nft_set_pipapo.c", "net/netfilter/nft_set_pipapo.h" ], "versions": [ { "version": "3c4287f62044a90e73a561aa05fc46e62da173da", "lessThan": "65ca51b9fb85477ab92a04295aed34b38f7c062e", "status": "affected", "versionType": "git" }, { "version": "3c4287f62044a90e73a561aa05fc46e62da173da", "lessThan": "c0f1f85097ac2b6e7d750fe4d05807985cd3fd3a", "status": "affected", "versionType": "git" }, { "version": "3c4287f62044a90e73a561aa05fc46e62da173da", "lessThan": "16f3595c0441d87dfa005c47d8f95be213afaa9e", "status": "affected", "versionType": "git" }, { "version": "3c4287f62044a90e73a561aa05fc46e62da173da", "lessThan": "7864c667aed01a58b87ca518a631322cd0ac34c0", "status": "affected", "versionType": "git" }, { "version": "3c4287f62044a90e73a561aa05fc46e62da173da", "lessThan": "c12d570d71920903a1a0468b7d13b085203d0c93", "status": "affected", "versionType": "git" }, { "version": "3c4287f62044a90e73a561aa05fc46e62da173da", "lessThan": "500a50a301ce962b019ab95053ac70264fec2c21", "status": "affected", "versionType": "git" }, { "version": "3c4287f62044a90e73a561aa05fc46e62da173da", "lessThan": "aff13667708dfa0dce136b8efd81baa9fa6ef261", "status": "affected", "versionType": "git" }, { "version": "3c4287f62044a90e73a561aa05fc46e62da173da", "lessThan": "9df95785d3d8302f7c066050117b04cd3c2048c2", "status": "affected", "versionType": "git" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "include/net/netfilter/nf_tables.h", "net/netfilter/nf_tables_api.c", "net/netfilter/nft_set_pipapo.c", "net/netfilter/nft_set_pipapo.h" ], "versions": [ { "version": "5.6", "status": "affected" }, { "version": "0", "lessThan": "5.6", "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": "6.12.77", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.17", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.19.7", "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": "5.6", "versionEndExcluding": "5.10.253" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.6", "versionEndExcluding": "5.15.203" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.6", "versionEndExcluding": "6.1.167" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.6", "versionEndExcluding": "6.6.130" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", 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"https://git.kernel.org/stable/c/500a50a301ce962b019ab95053ac70264fec2c21" }, { "url": "https://git.kernel.org/stable/c/aff13667708dfa0dce136b8efd81baa9fa6ef261" }, { "url": "https://git.kernel.org/stable/c/9df95785d3d8302f7c066050117b04cd3c2048c2" } ], "title": "netfilter: nft_set_pipapo: split gc into unlink and reclaim phase", "x_generator": { "engine": "bippy-1.2.0" } }, "adp": [ { "x_adpType": "supplier", "providerMetadata": { "orgId": "0b142b55-0307-4c5a-b3c9-f314f3fb7c5e", "shortName": "siemens-SADP", "dateUpdated": "2026-07-14T12:46:40.525Z" }, "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" }, { 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