{"api_version":"1","generated_at":"2026-10-23T01:17:13+00:00","cve":"CVE-2026-98851","urls":{"html":"https://cve.report/CVE-2026-98851","api":"https://cve.report/api/cve/CVE-2026-98851.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-98851","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-98851"},"summary":{"title":"netfilter: nft_flow_offload: drop flowtable reference on init error path","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nnetfilter: nft_flow_offload: drop flowtable reference on init error path\n\nnft_flow_offload_init() bumps the flowtable use count with\nnft_use_inc() before calling nf_ct_netns_get().  When the latter\nfails, the error is returned as-is and the reference is leaked.\n\nThe upper layers do not balance it either: nf_tables_newexpr()\nclears expr->ops when the expression init callback fails, so the\nnft_expr_more() iteration in nft_rule_expr_deactivate() and\nnf_tables_rule_destroy() stops right before the failed expression\nand its ->destroy callback, which would drop the reference, never\nruns.\n\nEach failed rule addition therefore leaks one flowtable reference\nand the flowtable can no longer be removed: NFT_MSG_DELFLOWTABLE\nkeeps reporting -EBUSY even though no rule references it.\n\nSave the nf_ct_netns_get() return value and undo the nft_use_inc()\nwhen it fails, restoring the inc/dec pairing within\nnft_flow_offload_init() itself.","state":"PUBLISHED","assigner":"Linux","published_at":"2026-10-18 16:17:39","updated_at":"2026-10-21 13:21:49"},"problem_types":[],"metrics":[],"references":[{"url":"https://git.kernel.org/stable/c/4cd378423a33194a773c267fc58606d28fce95cf","name":"https://git.kernel.org/stable/c/4cd378423a33194a773c267fc58606d28fce95cf","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/64ac0cb574c740bf723affb79b646eeba920db6b","name":"https://git.kernel.org/stable/c/64ac0cb574c740bf723affb79b646eeba920db6b","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/1d27214fd9a4d2c0c6d998fc9d4fb61448a3438e","name":"https://git.kernel.org/stable/c/1d27214fd9a4d2c0c6d998fc9d4fb61448a3438e","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/747928b5d4ff8c8de55138a54c13980e4bb88578","name":"https://git.kernel.org/stable/c/747928b5d4ff8c8de55138a54c13980e4bb88578","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/c5f91098edee98c015f78488460a0609e62582a5","name":"https://git.kernel.org/stable/c/c5f91098edee98c015f78488460a0609e62582a5","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-98851","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-98851","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected a3c90f7a2323b331ae816d5b0633e68148e25d04 1d27214fd9a4d2c0c6d998fc9d4fb61448a3438e git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected a3c90f7a2323b331ae816d5b0633e68148e25d04 64ac0cb574c740bf723affb79b646eeba920db6b git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected a3c90f7a2323b331ae816d5b0633e68148e25d04 c5f91098edee98c015f78488460a0609e62582a5 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected a3c90f7a2323b331ae816d5b0633e68148e25d04 4cd378423a33194a773c267fc58606d28fce95cf git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected a3c90f7a2323b331ae816d5b0633e68148e25d04 747928b5d4ff8c8de55138a54c13980e4bb88578 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 4.16","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 4.16 semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.6.160 6.6.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.12.113 6.12.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.18.56 6.18.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.2.10 7.2.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.3 * original_commit_for_fix","platforms":[]}],"timeline":[],"solutions":[],"workarounds":[],"exploits":[],"credits":[],"nvd_cpes":[],"vendor_comments":[],"enrichments":{"kev":null,"epss":{"cve_year":"2026","cve_id":"98851","cve":"CVE-2026-98851","epss":"0.001570000","percentile":"0.044450000","score_date":"2026-10-21","updated_at":"2026-10-22 00:15:10"},"legacy_qids":[]},"source_records":{"cve_program":{"containers":{"cna":{"affected":[{"defaultStatus":"unaffected","product":"Linux","programFiles":["net/netfilter/nft_flow_offload.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"lessThan":"1d27214fd9a4d2c0c6d998fc9d4fb61448a3438e","status":"affected","version":"a3c90f7a2323b331ae816d5b0633e68148e25d04","versionType":"git"},{"lessThan":"64ac0cb574c740bf723affb79b646eeba920db6b","status":"affected","version":"a3c90f7a2323b331ae816d5b0633e68148e25d04","versionType":"git"},{"lessThan":"c5f91098edee98c015f78488460a0609e62582a5","status":"affected","version":"a3c90f7a2323b331ae816d5b0633e68148e25d04","versionType":"git"},{"lessThan":"4cd378423a33194a773c267fc58606d28fce95cf","status":"affected","version":"a3c90f7a2323b331ae816d5b0633e68148e25d04","versionType":"git"},{"lessThan":"747928b5d4ff8c8de55138a54c13980e4bb88578","status":"affected","version":"a3c90f7a2323b331ae816d5b0633e68148e25d04","versionType":"git"}]},{"defaultStatus":"affected","product":"Linux","programFiles":["net/netfilter/nft_flow_offload.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"status":"affected","version":"4.16"},{"lessThan":"4.16","status":"unaffected","version":"0","versionType":"semver"},{"lessThanOrEqual":"6.6.*","status":"unaffected","version":"6.6.160","versionType":"semver"},{"lessThanOrEqual":"6.12.*","status":"unaffected","version":"6.12.113","versionType":"semver"},{"lessThanOrEqual":"6.18.*","status":"unaffected","version":"6.18.56","versionType":"semver"},{"lessThanOrEqual":"7.2.*","status":"unaffected","version":"7.2.10","versionType":"semver"},{"lessThanOrEqual":"*","status":"unaffected","version":"7.3","versionType":"original_commit_for_fix"}]}],"cpeApplicability":[{"nodes":[{"cpeMatch":[{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.6.160","versionStartIncluding":"4.16","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.12.113","versionStartIncluding":"4.16","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.18.56","versionStartIncluding":"4.16","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.2.10","versionStartIncluding":"4.16","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.3","versionStartIncluding":"4.16","vulnerable":true}],"negate":false,"operator":"OR"}]}],"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nnetfilter: nft_flow_offload: drop flowtable reference on init error path\n\nnft_flow_offload_init() bumps the flowtable use count with\nnft_use_inc() before calling nf_ct_netns_get().  When the latter\nfails, the error is returned as-is and the reference is leaked.\n\nThe upper layers do not balance it either: nf_tables_newexpr()\nclears expr->ops when the expression init callback fails, so the\nnft_expr_more() iteration in nft_rule_expr_deactivate() and\nnf_tables_rule_destroy() stops right before the failed expression\nand its ->destroy callback, which would drop the reference, never\nruns.\n\nEach failed rule addition therefore leaks one flowtable reference\nand the flowtable can no longer be removed: NFT_MSG_DELFLOWTABLE\nkeeps reporting -EBUSY even though no rule references it.\n\nSave the nf_ct_netns_get() return value and undo the nft_use_inc()\nwhen it fails, restoring the inc/dec pairing within\nnft_flow_offload_init() itself."}],"providerMetadata":{"dateUpdated":"2026-10-21T12:57:30.875Z","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux"},"references":[{"url":"https://git.kernel.org/stable/c/1d27214fd9a4d2c0c6d998fc9d4fb61448a3438e"},{"url":"https://git.kernel.org/stable/c/64ac0cb574c740bf723affb79b646eeba920db6b"},{"url":"https://git.kernel.org/stable/c/c5f91098edee98c015f78488460a0609e62582a5"},{"url":"https://git.kernel.org/stable/c/4cd378423a33194a773c267fc58606d28fce95cf"},{"url":"https://git.kernel.org/stable/c/747928b5d4ff8c8de55138a54c13980e4bb88578"}],"title":"netfilter: nft_flow_offload: drop flowtable reference on init error path","x_generator":{"engine":"bippy-1.2.0"}}},"cveMetadata":{"assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","assignerShortName":"Linux","cveId":"CVE-2026-98851","datePublished":"2026-10-18T15:50:50.910Z","dateReserved":"2026-09-25T10:25:14.376Z","dateUpdated":"2026-10-21T12:57:30.875Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-10-18 16:17:39","lastModifiedDate":"2026-10-21 13:21:49","problem_types":[],"metrics":[],"configurations":[]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"98851","Ordinal":"1","Title":"netfilter: nft_flow_offload: drop flowtable reference on init er","CVE":"CVE-2026-98851","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"98851","Ordinal":"1","NoteData":"In the Linux kernel, the following vulnerability has been resolved:\n\nnetfilter: nft_flow_offload: drop flowtable reference on init error path\n\nnft_flow_offload_init() bumps the flowtable use count with\nnft_use_inc() before calling nf_ct_netns_get().  When the latter\nfails, the error is returned as-is and the reference is leaked.\n\nThe upper layers do not balance it either: nf_tables_newexpr()\nclears expr->ops when the expression init callback fails, so the\nnft_expr_more() iteration in nft_rule_expr_deactivate() and\nnf_tables_rule_destroy() stops right before the failed expression\nand its ->destroy callback, which would drop the reference, never\nruns.\n\nEach failed rule addition therefore leaks one flowtable reference\nand the flowtable can no longer be removed: NFT_MSG_DELFLOWTABLE\nkeeps reporting -EBUSY even though no rule references it.\n\nSave the nf_ct_netns_get() return value and undo the nft_use_inc()\nwhen it fails, restoring the inc/dec pairing within\nnft_flow_offload_init() itself.","Type":"Description","Title":"netfilter: nft_flow_offload: drop flowtable reference on init er"}]}}}