{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-23272", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-01-13T15:37:45.991Z", "datePublished": "2026-03-20T08:08:52.946Z", "dateUpdated": "2026-08-05T12:21:02.795Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T12:21:02.795Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnetfilter: nf_tables: unconditionally bump set->nelems before insertion\n\nIn case that the set is full, a new element gets published then removed\nwithout waiting for the RCU grace period, while RCU reader can be\nwalking over it already.\n\nTo address this issue, add the element transaction even if set is full,\nbut toggle the set_full flag to report -ENFILE so the abort path safely\nunwinds the set to its previous state.\n\nAs for element updates, decrement set->nelems to restore it.\n\nA simpler fix is to call synchronize_rcu() in the error path.\nHowever, with a large batch adding elements to already maxed-out set,\nthis could cause noticeable slowdown of such batches." } ], "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 nfnetlink sockets which require local system access (netlink socket). This is not remotely reachable.\nAC:L - The attacker controls the conditions: they fill the set to maximum, then insert another element to trigger the UAF. While the RCU reader race exists, the attacker controls both the insertion and can arrange for concurrent lookups, making the race reliably triggerable.\nPR:L - nfnetlink requires CAP_NET_ADMIN, but nftables is per-network-namespace and reachable via user namespaces (unshare -Urn), so an unprivileged local user can obtain CAP_NET_ADMIN in a new namespace.\nUI:N - No user interaction is needed. The attacker can trigger this entirely through their own netlink socket operations.\nS:U - The vulnerability operates within the kernel's security authority. There is no crossing of a security boundary like VM escape or sandbox escape.\nC:H - This is a use-after-free where an RCU reader accesses freed memory. The freed memory can be reclaimed and filled with attacker-controlled data via heap spraying, enabling arbitrary kernel memory reads.\nI:H - Use-after-free in the kernel enables heap spraying and type confusion, allowing arbitrary write primitives and control flow hijacking for code execution.\nA:H - The UAF can cause kernel crashes (oops/panic) when RCU readers access freed or corrupted memory. Even without full exploitation, the bug reliably causes availability impact." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "net/netfilter/nf_tables_api.c" ], "versions": [ { "version": "35d0ac9070ef619e3bf44324375878a1c540387b", "lessThan": "25fcaef7948912652905e96922f36583a84fffed", "status": "affected", "versionType": "git" }, { "version": "35d0ac9070ef619e3bf44324375878a1c540387b", "lessThan": "e3ccb11fc8249759d23326038c8db987ddaabc77", "status": "affected", "versionType": "git" }, { "version": "35d0ac9070ef619e3bf44324375878a1c540387b", "lessThan": "86bc4b1a0f672d47ac19f9022432cb6a2e01cb33", "status": "affected", "versionType": "git" }, { "version": "35d0ac9070ef619e3bf44324375878a1c540387b", "lessThan": "6826131c7674329335ca25df2550163eb8a1fd0c", "status": "affected", "versionType": "git" }, { "version": "35d0ac9070ef619e3bf44324375878a1c540387b", "lessThan": "ccb8c8f3c1127cf34d18c737309897c68046bf21", "status": "affected", "versionType": "git" }, { "version": "35d0ac9070ef619e3bf44324375878a1c540387b", "lessThan": "def602e498a4f951da95c95b1b8ce8ae68aa733a", "status": "affected", "versionType": "git" }, { "version": "fefdd79403e89b0c673965343b92e2e01e2713a8", "status": "affected", "versionType": "git" }, { "version": "4.9.33", "lessThan": "4.10", "status": "affected", "versionType": "semver" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "net/netfilter/nf_tables_api.c" ], "versions": [ { "version": "4.10", "status": "affected" }, { "version": "0", "lessThan": "4.10", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.177", "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": "6.18.17", "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": "4.10", "versionEndExcluding": "6.1.177" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.10", "versionEndExcluding": "6.6.141" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.10", "versionEndExcluding": "6.12.91" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.10", "versionEndExcluding": "6.18.17" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.10", "versionEndExcluding": "6.19.7" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.10", "versionEndExcluding": "7.0" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.9.33" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/25fcaef7948912652905e96922f36583a84fffed" }, { "url": "https://git.kernel.org/stable/c/e3ccb11fc8249759d23326038c8db987ddaabc77" }, { "url": "https://git.kernel.org/stable/c/86bc4b1a0f672d47ac19f9022432cb6a2e01cb33" }, { "url": "https://git.kernel.org/stable/c/6826131c7674329335ca25df2550163eb8a1fd0c" }, { "url": "https://git.kernel.org/stable/c/ccb8c8f3c1127cf34d18c737309897c68046bf21" }, { "url": "https://git.kernel.org/stable/c/def602e498a4f951da95c95b1b8ce8ae68aa733a" } ], "title": "netfilter: nf_tables: unconditionally bump set->nelems before insertion", "x_generator": { "engine": "bippy-1.2.0" } } } }