{"api_version":"1","generated_at":"2026-08-28T12:13:46+00:00","cve":"CVE-2026-80668","urls":{"html":"https://cve.report/CVE-2026-80668","api":"https://cve.report/api/cve/CVE-2026-80668.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-80668","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-80668"},"summary":{"title":"netfilter: nf_conntrack_expect: use conntrack GC to reap expectations","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nnetfilter: nf_conntrack_expect: use conntrack GC to reap expectations\n\nThis patch replaces the timer API by GC worker approach for\nexpectations, as it already happened in many other subsystems.\n\nUse the existing conntrack GC worker to iterate over the local list of\nexpectations in the master conntrack to reap expired expectations.\nCheck IPS_HELPER_BIT to run GC for expectations, set it on for nft_ct\nexpectation which nevers sets it. Hold the expectation spinlock while\niterating over the master conntrack expectation list to synchronize with\nnf_ct_remove_expectations(). This also performs runtime packet path\ngarbage collection through the expectation insertion and lookup\nfunctions while walking over one of the chains of the global expectation\nhashtables. Unconfirmed conntrack entries are skipped since ct->ext can\nbe reallocated and dying are skipped since those will be gone soon.\nSet on IPS_HELPER_BIT if the helper ct extension is added, then the new\nGC worker does not need to bump the ct refcount to check if the ct->ext\nhelper is available.\n\nThis removes the extra bump on the refcount for expectation timers, this\nallows to remove several nf_ct_expect_put() calls after the unlink,\nafter this update only refcount remains at 1 while on the expectation\nhashes.\n\nThis patch implicitly addresses a race with the existing timer API\nallowing an expectation to access a stale exp->master pointer which has\nbeen already released when expectation removal loses races with an\nexpiring timer, ie. timer_del() reporting false.\n\nAdd a new NF_CT_EXPECT_DEAD flag to reap this expectation via GC. This\nis needed by nf_conntrack_unexpect_related() which is called in error\npaths to invalidate newly created expectations that has been added into\nthe hashes. These expectactions cannot be inmediately released as GC or\nnf_ct_remove_expectations() could race to make it. On expectation\ninsert, the runtime GC reaps stale expectations before checking the\nexpectation limit set by policy.\n\nSet current timestamp in nf_ct_expect_alloc(), then add the expectation\npolicy timeout (or custom timeout specified added on top of this) to\nspecify the expectation lifetime.","state":"PUBLISHED","assigner":"Linux","published_at":"2026-08-28 08:16:52","updated_at":"2026-08-28 08:16:52"},"problem_types":[],"metrics":[],"references":[{"url":"https://git.kernel.org/stable/c/b8b09dc2bf35a00d4e0556b5d6308c7b917ebda2","name":"https://git.kernel.org/stable/c/b8b09dc2bf35a00d4e0556b5d6308c7b917ebda2","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/7ec786f4230c2a9b2eaf97a2d45368933b49d2b2","name":"https://git.kernel.org/stable/c/7ec786f4230c2a9b2eaf97a2d45368933b49d2b2","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-80668","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-80668","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected bffcaad9afdfe45d7fc777397d3b83c1e3ebffe5 7ec786f4230c2a9b2eaf97a2d45368933b49d2b2 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected bffcaad9afdfe45d7fc777397d3b83c1e3ebffe5 b8b09dc2bf35a00d4e0556b5d6308c7b917ebda2 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 9e1196d27ef496f404c76f7a9d03761142d991c4 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 5e1c1d22268ae710c238342c8030c21daf298168 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected d52fa1fa7440676b8c238037a050ab008c22737f git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected f338ced0473849c9f6ed0b77ca99f1aab5826787 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 497f99b26fffdc5635706d1b4811f1ed8ee21a5b git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 6.1.176 6.2 semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 6.6.143 6.7 semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 6.12.94 6.13 semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 6.18.24 6.19 semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 6.19.14 6.20 semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 7.0","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.0 semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.1.5 7.1.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.2 * original_commit_for_fix","platforms":[]}],"timeline":[],"solutions":[],"workarounds":[],"exploits":[],"credits":[],"nvd_cpes":[],"vendor_comments":[],"enrichments":{"kev":null,"epss":null,"legacy_qids":[]},"source_records":{"cve_program":{"containers":{"cna":{"affected":[{"defaultStatus":"unaffected","product":"Linux","programFiles":["include/net/netfilter/nf_conntrack_expect.h","include/uapi/linux/netfilter/nf_conntrack_common.h","net/netfilter/nf_conntrack_core.c","net/netfilter/nf_conntrack_expect.c","net/netfilter/nf_conntrack_h323_main.c","net/netfilter/nf_conntrack_helper.c","net/netfilter/nf_conntrack_netlink.c","net/netfilter/nf_conntrack_sip.c","net/netfilter/nft_ct.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"lessThan":"7ec786f4230c2a9b2eaf97a2d45368933b49d2b2","status":"affected","version":"bffcaad9afdfe45d7fc777397d3b83c1e3ebffe5","versionType":"git"},{"lessThan":"b8b09dc2bf35a00d4e0556b5d6308c7b917ebda2","status":"affected","version":"bffcaad9afdfe45d7fc777397d3b83c1e3ebffe5","versionType":"git"},{"status":"affected","version":"9e1196d27ef496f404c76f7a9d03761142d991c4","versionType":"git"},{"status":"affected","version":"5e1c1d22268ae710c238342c8030c21daf298168","versionType":"git"},{"status":"affected","version":"d52fa1fa7440676b8c238037a050ab008c22737f","versionType":"git"},{"status":"affected","version":"f338ced0473849c9f6ed0b77ca99f1aab5826787","versionType":"git"},{"status":"affected","version":"497f99b26fffdc5635706d1b4811f1ed8ee21a5b","versionType":"git"},{"lessThan":"6.2","status":"affected","version":"6.1.176","versionType":"semver"},{"lessThan":"6.7","status":"affected","version":"6.6.143","versionType":"semver"},{"lessThan":"6.13","status":"affected","version":"6.12.94","versionType":"semver"},{"lessThan":"6.19","status":"affected","version":"6.18.24","versionType":"semver"},{"lessThan":"6.20","status":"affected","version":"6.19.14","versionType":"semver"}]},{"defaultStatus":"affected","product":"Linux","programFiles":["include/net/netfilter/nf_conntrack_expect.h","include/uapi/linux/netfilter/nf_conntrack_common.h","net/netfilter/nf_conntrack_core.c","net/netfilter/nf_conntrack_expect.c","net/netfilter/nf_conntrack_h323_main.c","net/netfilter/nf_conntrack_helper.c","net/netfilter/nf_conntrack_netlink.c","net/netfilter/nf_conntrack_sip.c","net/netfilter/nft_ct.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"status":"affected","version":"7.0"},{"lessThan":"7.0","status":"unaffected","version":"0","versionType":"semver"},{"lessThanOrEqual":"7.1.*","status":"unaffected","version":"7.1.5","versionType":"semver"},{"lessThanOrEqual":"*","status":"unaffected","version":"7.2","versionType":"original_commit_for_fix"}]}],"cpeApplicability":[{"nodes":[{"cpeMatch":[{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.1.5","versionStartIncluding":"7.0","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.2","versionStartIncluding":"7.0","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.1.176","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.6.143","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.12.94","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.18.24","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.19.14","vulnerable":true}],"negate":false,"operator":"OR"}]}],"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nnetfilter: nf_conntrack_expect: use conntrack GC to reap expectations\n\nThis patch replaces the timer API by GC worker approach for\nexpectations, as it already happened in many other subsystems.\n\nUse the existing conntrack GC worker to iterate over the local list of\nexpectations in the master conntrack to reap expired expectations.\nCheck IPS_HELPER_BIT to run GC for expectations, set it on for nft_ct\nexpectation which nevers sets it. Hold the expectation spinlock while\niterating over the master conntrack expectation list to synchronize with\nnf_ct_remove_expectations(). This also performs runtime packet path\ngarbage collection through the expectation insertion and lookup\nfunctions while walking over one of the chains of the global expectation\nhashtables. Unconfirmed conntrack entries are skipped since ct->ext can\nbe reallocated and dying are skipped since those will be gone soon.\nSet on IPS_HELPER_BIT if the helper ct extension is added, then the new\nGC worker does not need to bump the ct refcount to check if the ct->ext\nhelper is available.\n\nThis removes the extra bump on the refcount for expectation timers, this\nallows to remove several nf_ct_expect_put() calls after the unlink,\nafter this update only refcount remains at 1 while on the expectation\nhashes.\n\nThis patch implicitly addresses a race with the existing timer API\nallowing an expectation to access a stale exp->master pointer which has\nbeen already released when expectation removal loses races with an\nexpiring timer, ie. timer_del() reporting false.\n\nAdd a new NF_CT_EXPECT_DEAD flag to reap this expectation via GC. This\nis needed by nf_conntrack_unexpect_related() which is called in error\npaths to invalidate newly created expectations that has been added into\nthe hashes. These expectactions cannot be inmediately released as GC or\nnf_ct_remove_expectations() could race to make it. On expectation\ninsert, the runtime GC reaps stale expectations before checking the\nexpectation limit set by policy.\n\nSet current timestamp in nf_ct_expect_alloc(), then add the expectation\npolicy timeout (or custom timeout specified added on top of this) to\nspecify the expectation lifetime."}],"providerMetadata":{"dateUpdated":"2026-08-28T06:49:09.877Z","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux"},"references":[{"url":"https://git.kernel.org/stable/c/7ec786f4230c2a9b2eaf97a2d45368933b49d2b2"},{"url":"https://git.kernel.org/stable/c/b8b09dc2bf35a00d4e0556b5d6308c7b917ebda2"}],"title":"netfilter: nf_conntrack_expect: use conntrack GC to reap expectations","x_generator":{"engine":"bippy-1.2.0"}}},"cveMetadata":{"assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","assignerShortName":"Linux","cveId":"CVE-2026-80668","datePublished":"2026-08-28T06:49:09.877Z","dateReserved":"2026-08-26T14:34:25.782Z","dateUpdated":"2026-08-28T06:49:09.877Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-08-28 08:16:52","lastModifiedDate":"2026-08-28 08:16:52","problem_types":[],"metrics":[],"configurations":[]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"80668","Ordinal":"1","Title":"netfilter: nf_conntrack_expect: use conntrack GC to reap expecta","CVE":"CVE-2026-80668","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"80668","Ordinal":"1","NoteData":"In the Linux kernel, the following vulnerability has been resolved:\n\nnetfilter: nf_conntrack_expect: use conntrack GC to reap expectations\n\nThis patch replaces the timer API by GC worker approach for\nexpectations, as it already happened in many other subsystems.\n\nUse the existing conntrack GC worker to iterate over the local list of\nexpectations in the master conntrack to reap expired expectations.\nCheck IPS_HELPER_BIT to run GC for expectations, set it on for nft_ct\nexpectation which nevers sets it. Hold the expectation spinlock while\niterating over the master conntrack expectation list to synchronize with\nnf_ct_remove_expectations(). This also performs runtime packet path\ngarbage collection through the expectation insertion and lookup\nfunctions while walking over one of the chains of the global expectation\nhashtables. Unconfirmed conntrack entries are skipped since ct->ext can\nbe reallocated and dying are skipped since those will be gone soon.\nSet on IPS_HELPER_BIT if the helper ct extension is added, then the new\nGC worker does not need to bump the ct refcount to check if the ct->ext\nhelper is available.\n\nThis removes the extra bump on the refcount for expectation timers, this\nallows to remove several nf_ct_expect_put() calls after the unlink,\nafter this update only refcount remains at 1 while on the expectation\nhashes.\n\nThis patch implicitly addresses a race with the existing timer API\nallowing an expectation to access a stale exp->master pointer which has\nbeen already released when expectation removal loses races with an\nexpiring timer, ie. timer_del() reporting false.\n\nAdd a new NF_CT_EXPECT_DEAD flag to reap this expectation via GC. This\nis needed by nf_conntrack_unexpect_related() which is called in error\npaths to invalidate newly created expectations that has been added into\nthe hashes. These expectactions cannot be inmediately released as GC or\nnf_ct_remove_expectations() could race to make it. On expectation\ninsert, the runtime GC reaps stale expectations before checking the\nexpectation limit set by policy.\n\nSet current timestamp in nf_ct_expect_alloc(), then add the expectation\npolicy timeout (or custom timeout specified added on top of this) to\nspecify the expectation lifetime.","Type":"Description","Title":"netfilter: nf_conntrack_expect: use conntrack GC to reap expecta"}]}}}