{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-63858", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-07-19T07:54:57.016Z", "datePublished": "2026-07-19T14:04:46.967Z", "dateUpdated": "2026-08-05T12:36:37.055Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T12:36:37.055Z" }, "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." } ], "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." } ] } ], "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" ], "versions": [ { "version": "b6d9014a3335194590abdd2a2471ef5147a67645", "lessThan": "4e69bfb32b2db323d9205fdb30e284481b37817c", "status": "affected", "versionType": "git" }, { "version": "b6d9014a3335194590abdd2a2471ef5147a67645", "lessThan": "10f79dbd7719d1da9f5884d13060322d8729f091", "status": "affected", "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", "lessThan": "5.11", "status": "affected", "versionType": "semver" }, { "version": "5.15.47", "lessThan": "5.16", "status": "affected", "versionType": "semver" }, { "version": "5.17.15", "lessThan": "5.18", "status": "affected", "versionType": "semver" }, { "version": "5.18.4", "lessThan": "5.19", "status": "affected", "versionType": "semver" } ] }, { "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" ], "versions": [ { "version": "5.19", "status": "affected" }, { "version": "0", "lessThan": "5.19", "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": "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" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/4e69bfb32b2db323d9205fdb30e284481b37817c" }, { "url": "https://git.kernel.org/stable/c/10f79dbd7719d1da9f5884d13060322d8729f091" } ], "title": "netfilter: nf_tables: add hook transactions for device deletions", "x_generator": { "engine": "bippy-1.2.0" } } } }