{"id":"CVE-2026-63858","state":"PUBLISHED","title":"netfilter: nf_tables: add hook transactions for device deletions","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nnetfilter: nf_tables: add hook transactions for device deletions\n\nRestore the flag that indicates that the hook is going away, ie.\nNFT_HOOK_REMOVE, but add a new transaction object to track deletion\nof hooks without altering the basechain/flowtable hook_list during\nthe preparation phase.\n\nThe existing approach that moves the hook from the basechain/flowtable\nhook_list to transaction hook_list breaks netlink dump path readers\nof this RCU-protected list.\n\nIt should be possible use an array for nft_trans_hook to store the\ndeleted hooks to compact the representation but I am not expecting\nmany hook object, specially now that wildcard support for devices\nis in place.\n\nNote that the nft_trans_chain_hooks() list contains a list of struct\nnft_trans_hook objects for DELCHAIN and DELFLOWTABLE commands, while\nthis list stores struct nft_hook objects for NEWCHAIN and NEWFLOWTABLE.\nNote that new commands can be updated to use nft_trans_hook for\nconsistency.\n\nThis patch also adapts the event notification path to deal with the list\nof hook transactions.","publishedAt":"2026-07-19T14:04:46.967Z","updatedAt":"2026-10-19T20:07:52.230Z","severity":{"score":7.8,"label":"High","version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","source":"Linux"},"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"b6d9014a3335194590abdd2a2471ef5147a67645","status":"affected","lessThan":"768daa9f4276be4007e88dea61a378c8582ba008","versionType":"git"},{"version":"b6d9014a3335194590abdd2a2471ef5147a67645","status":"affected","lessThan":"4e69bfb32b2db323d9205fdb30e284481b37817c","versionType":"git"},{"version":"b6d9014a3335194590abdd2a2471ef5147a67645","status":"affected","lessThan":"10f79dbd7719d1da9f5884d13060322d8729f091","versionType":"git"},{"version":"7a248f9c74f9f62799718c12efd9e9e391d60b6f","status":"affected","versionType":"git"},{"version":"f275989ad04159dbfc62cefb65ba9c5ba1d7c34f","status":"affected","versionType":"git"},{"version":"62d91062058b42bf70b2c3446aec397bb0ce15ee","status":"affected","versionType":"git"},{"version":"99180dec5ae582227219d1fdd0dd5ccf53ec7491","status":"affected","versionType":"git"},{"version":"5.10.122","status":"affected","lessThan":"5.11","versionType":"semver"},{"version":"5.15.47","status":"affected","lessThan":"5.16","versionType":"semver"},{"version":"5.17.15","status":"affected","lessThan":"5.18","versionType":"semver"},{"version":"5.18.4","status":"affected","lessThan":"5.19","versionType":"semver"}],"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"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"5.19","status":"affected"},{"version":"0","status":"unaffected","lessThan":"5.19","versionType":"semver"},{"version":"6.18.57","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.0.10","status":"unaffected","lessThanOrEqual":"7.0.*","versionType":"semver"},{"version":"7.1","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"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"]}],"references":["https://git.kernel.org/stable/c/768daa9f4276be4007e88dea61a378c8582ba008","https://git.kernel.org/stable/c/4e69bfb32b2db323d9205fdb30e284481b37817c","https://git.kernel.org/stable/c/10f79dbd7719d1da9f5884d13060322d8729f091"],"weaknesses":["CWE-362"],"ingestedAt":"2026-10-29T20:12:41.951Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/63xxx/CVE-2026-63858.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-63858","state":"PUBLISHED","datePublished":"2026-07-19T14:04:46.967Z","dateUpdated":"2026-10-19T20:07:52.230Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-07-19T07:54:57.016Z"},"containers":{"cna":{"title":"netfilter: nf_tables: add hook transactions for device deletions","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nnetfilter: nf_tables: add hook transactions for device deletions\n\nRestore the flag that indicates that the hook is going away, ie.\nNFT_HOOK_REMOVE, but add a new transaction object to track deletion\nof hooks without altering the basechain/flowtable hook_list during\nthe preparation phase.\n\nThe existing approach that moves the hook from the basechain/flowtable\nhook_list to transaction hook_list breaks netlink dump path readers\nof this RCU-protected list.\n\nIt should be possible use an array for nft_trans_hook to store the\ndeleted hooks to compact the representation but I am not expecting\nmany hook object, specially now that wildcard support for devices\nis in place.\n\nNote that the nft_trans_chain_hooks() list contains a list of struct\nnft_trans_hook objects for DELCHAIN and DELFLOWTABLE commands, while\nthis list stores struct nft_hook objects for NEWCHAIN and NEWFLOWTABLE.\nNote that new commands can be updated to use nft_trans_hook for\nconsistency.\n\nThis patch also adapts the event notification path to deal with the list\nof hook transactions."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"b6d9014a3335194590abdd2a2471ef5147a67645","status":"affected","lessThan":"768daa9f4276be4007e88dea61a378c8582ba008","versionType":"git"},{"version":"b6d9014a3335194590abdd2a2471ef5147a67645","status":"affected","lessThan":"4e69bfb32b2db323d9205fdb30e284481b37817c","versionType":"git"},{"version":"b6d9014a3335194590abdd2a2471ef5147a67645","status":"affected","lessThan":"10f79dbd7719d1da9f5884d13060322d8729f091","versionType":"git"},{"version":"7a248f9c74f9f62799718c12efd9e9e391d60b6f","status":"affected","versionType":"git"},{"version":"f275989ad04159dbfc62cefb65ba9c5ba1d7c34f","status":"affected","versionType":"git"},{"version":"62d91062058b42bf70b2c3446aec397bb0ce15ee","status":"affected","versionType":"git"},{"version":"99180dec5ae582227219d1fdd0dd5ccf53ec7491","status":"affected","versionType":"git"},{"version":"5.10.122","status":"affected","lessThan":"5.11","versionType":"semver"},{"version":"5.15.47","status":"affected","lessThan":"5.16","versionType":"semver"},{"version":"5.17.15","status":"affected","lessThan":"5.18","versionType":"semver"},{"version":"5.18.4","status":"affected","lessThan":"5.19","versionType":"semver"}],"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"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"5.19","status":"affected"},{"version":"0","status":"unaffected","lessThan":"5.19","versionType":"semver"},{"version":"6.18.57","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.0.10","status":"unaffected","lessThanOrEqual":"7.0.*","versionType":"semver"},{"version":"7.1","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"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"]}],"references":[{"url":"https://git.kernel.org/stable/c/768daa9f4276be4007e88dea61a378c8582ba008"},{"url":"https://git.kernel.org/stable/c/4e69bfb32b2db323d9205fdb30e284481b37817c"},{"url":"https://git.kernel.org/stable/c/10f79dbd7719d1da9f5884d13060322d8729f091"}],"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 - The vulnerability is reachable only through local Netlink syscalls to the nf_tables subsystem (NFT_MSG_DELCHAIN/DELFLOWTABLE hook deletion racing with GETCHAIN/GETFLOWTABLE dumps), which per kernel CNA guidance is Attack Vector Local, not network-reachable.\nAC:L - The attacker controls both sides of the race by opening concurrent Netlink sockets—one issuing hook-deletion batch commands and another issuing chain/flowtable dumps—making successful triggering reliably achievable without conditions outside attacker control.\nPR:L - All nf_tables Netlink operations require CAP_NET_ADMIN checked in nfnetlink_rcv(), which is obtainable by an unprivileged user via user namespaces (unshare -Urn), so privileges required are Low rather than High.\nUI:N - Exploitation requires no victim interaction; the attacker triggers the race entirely through their own concurrent Netlink requests without needing another user to perform any action.\nS:U - Impact remains within the kernel's security authority (kernel crash, memory corruption, potential local privilege escalation) rather than crossing a distinct security boundary such as VM guest-to-host escape.\nC:H - RCU list corruption yields a bogus nft_hook pointer that dereferences arbitrary kernel memory (e.g., reading hook->ifname from stack-local or freed memory), constituting arbitrary kernel memory read potential consistent with High confidentiality impact.\nI:H - The corrupted list traversal produces invalid struct nft_hook pointers via container_of(), enabling heap/stack memory corruption that can be leveraged for arbitrary write or control-flow hijacking, warranting High integrity impact.\nA:H - The race reliably causes kernel oops/panic from dereferencing bogus nft_hook pointers during concurrent Netlink dumps, and the underlying RCU list corruption can crash or hang the system, giving High availability impact."}]}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-10-15T10:07:50.587Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.19","versionEndExcluding":"6.18.57"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.19","versionEndExcluding":"7.0.10"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.19","versionEndExcluding":"7.1"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.10.122"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.15.47"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.17.15"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.18.4"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"id":"CVE-2026-63858","role":"CISA Coordinator","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"total"}],"version":"2.0.3","timestamp":"2026-10-16T15:32:27.434041Z"}}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-362","lang":"en","type":"CWE","description":"CWE-362 Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')"}]}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-10-19T20:07:52.230Z"}}]}}}