{"api_version":"1","generated_at":"2026-05-01T19:27:28+00:00","cve":"CVE-2026-43027","urls":{"html":"https://cve.report/CVE-2026-43027","api":"https://cve.report/api/cve/CVE-2026-43027.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-43027","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-43027"},"summary":{"title":"netfilter: nf_conntrack_helper: pass helper to expect cleanup","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nnetfilter: nf_conntrack_helper: pass helper to expect cleanup\n\nnf_conntrack_helper_unregister() calls nf_ct_expect_iterate_destroy()\nto remove expectations belonging to the helper being unregistered.\nHowever, it passes NULL instead of the helper pointer as the data\nargument, so expect_iter_me() never matches any expectation and all\nof them survive the cleanup.\n\nAfter unregister returns, nfnl_cthelper_del() frees the helper\nobject immediately.  Subsequent expectation dumps or packet-driven\ninit_conntrack() calls then dereference the freed exp->helper,\ncausing a use-after-free.\n\nPass the actual helper pointer so expectations referencing it are\nproperly destroyed before the helper object is freed.\n\n  BUG: KASAN: slab-use-after-free in string+0x38f/0x430\n  Read of size 1 at addr ffff888003b14d20 by task poc/103\n  Call Trace:\n   string+0x38f/0x430\n   vsnprintf+0x3cc/0x1170\n   seq_printf+0x17a/0x240\n   exp_seq_show+0x2e5/0x560\n   seq_read_iter+0x419/0x1280\n   proc_reg_read+0x1ac/0x270\n   vfs_read+0x179/0x930\n   ksys_read+0xef/0x1c0\n  Freed by task 103:\n  The buggy address is located 32 bytes inside of\n   freed 192-byte region [ffff888003b14d00, ffff888003b14dc0)","state":"PUBLISHED","assigner":"Linux","published_at":"2026-05-01 15:16:47","updated_at":"2026-05-01 15:24:14"},"problem_types":[],"metrics":[],"references":[{"url":"https://git.kernel.org/stable/c/a242a9ae58aa46ff7dae51ce64150a93957abe65","name":"https://git.kernel.org/stable/c/a242a9ae58aa46ff7dae51ce64150a93957abe65","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/620f3d14c1ef51d425060a3056ad8dbae8f998a3","name":"https://git.kernel.org/stable/c/620f3d14c1ef51d425060a3056ad8dbae8f998a3","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/dc1739eff48e34cc71d4e2f03715493fbcebd8af","name":"https://git.kernel.org/stable/c/dc1739eff48e34cc71d4e2f03715493fbcebd8af","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/2c16e4d64dd91227742dfe196a3e7b0568bef65a","name":"https://git.kernel.org/stable/c/2c16e4d64dd91227742dfe196a3e7b0568bef65a","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/504ba4168466c91210c45acdc332479cfd5f2da6","name":"https://git.kernel.org/stable/c/504ba4168466c91210c45acdc332479cfd5f2da6","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/2cf2737c85a2ba2b52024dafe68ffad2676f97be","name":"https://git.kernel.org/stable/c/2cf2737c85a2ba2b52024dafe68ffad2676f97be","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/90bd7e8501349db3006d21fbc09df9ffcb172965","name":"https://git.kernel.org/stable/c/90bd7e8501349db3006d21fbc09df9ffcb172965","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/5cf28d5c8dcbbe8af6d3b145babe491906d7bad1","name":"https://git.kernel.org/stable/c/5cf28d5c8dcbbe8af6d3b145babe491906d7bad1","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-43027","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-43027","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected ac7b848390036dadd4351899d2a23748075916bd 5cf28d5c8dcbbe8af6d3b145babe491906d7bad1 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected ac7b848390036dadd4351899d2a23748075916bd 504ba4168466c91210c45acdc332479cfd5f2da6 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected ac7b848390036dadd4351899d2a23748075916bd dc1739eff48e34cc71d4e2f03715493fbcebd8af git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected ac7b848390036dadd4351899d2a23748075916bd 2cf2737c85a2ba2b52024dafe68ffad2676f97be git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected ac7b848390036dadd4351899d2a23748075916bd 2c16e4d64dd91227742dfe196a3e7b0568bef65a git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected ac7b848390036dadd4351899d2a23748075916bd 620f3d14c1ef51d425060a3056ad8dbae8f998a3 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected ac7b848390036dadd4351899d2a23748075916bd 90bd7e8501349db3006d21fbc09df9ffcb172965 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected ac7b848390036dadd4351899d2a23748075916bd a242a9ae58aa46ff7dae51ce64150a93957abe65 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 4.14","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 4.14 semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 5.10.253 5.10.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 5.15.203 5.15.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.1.168 6.1.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.6.134 6.6.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.12.81 6.12.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.18.22 6.18.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.19.12 6.19.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.0 * 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":["net/netfilter/nf_conntrack_helper.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"lessThan":"5cf28d5c8dcbbe8af6d3b145babe491906d7bad1","status":"affected","version":"ac7b848390036dadd4351899d2a23748075916bd","versionType":"git"},{"lessThan":"504ba4168466c91210c45acdc332479cfd5f2da6","status":"affected","version":"ac7b848390036dadd4351899d2a23748075916bd","versionType":"git"},{"lessThan":"dc1739eff48e34cc71d4e2f03715493fbcebd8af","status":"affected","version":"ac7b848390036dadd4351899d2a23748075916bd","versionType":"git"},{"lessThan":"2cf2737c85a2ba2b52024dafe68ffad2676f97be","status":"affected","version":"ac7b848390036dadd4351899d2a23748075916bd","versionType":"git"},{"lessThan":"2c16e4d64dd91227742dfe196a3e7b0568bef65a","status":"affected","version":"ac7b848390036dadd4351899d2a23748075916bd","versionType":"git"},{"lessThan":"620f3d14c1ef51d425060a3056ad8dbae8f998a3","status":"affected","version":"ac7b848390036dadd4351899d2a23748075916bd","versionType":"git"},{"lessThan":"90bd7e8501349db3006d21fbc09df9ffcb172965","status":"affected","version":"ac7b848390036dadd4351899d2a23748075916bd","versionType":"git"},{"lessThan":"a242a9ae58aa46ff7dae51ce64150a93957abe65","status":"affected","version":"ac7b848390036dadd4351899d2a23748075916bd","versionType":"git"}]},{"defaultStatus":"affected","product":"Linux","programFiles":["net/netfilter/nf_conntrack_helper.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"status":"affected","version":"4.14"},{"lessThan":"4.14","status":"unaffected","version":"0","versionType":"semver"},{"lessThanOrEqual":"5.10.*","status":"unaffected","version":"5.10.253","versionType":"semver"},{"lessThanOrEqual":"5.15.*","status":"unaffected","version":"5.15.203","versionType":"semver"},{"lessThanOrEqual":"6.1.*","status":"unaffected","version":"6.1.168","versionType":"semver"},{"lessThanOrEqual":"6.6.*","status":"unaffected","version":"6.6.134","versionType":"semver"},{"lessThanOrEqual":"6.12.*","status":"unaffected","version":"6.12.81","versionType":"semver"},{"lessThanOrEqual":"6.18.*","status":"unaffected","version":"6.18.22","versionType":"semver"},{"lessThanOrEqual":"6.19.*","status":"unaffected","version":"6.19.12","versionType":"semver"},{"lessThanOrEqual":"*","status":"unaffected","version":"7.0","versionType":"original_commit_for_fix"}]}],"cpeApplicability":[{"nodes":[{"cpeMatch":[{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"5.10.253","versionStartIncluding":"4.14","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"5.15.203","versionStartIncluding":"4.14","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.1.168","versionStartIncluding":"4.14","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.6.134","versionStartIncluding":"4.14","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.12.81","versionStartIncluding":"4.14","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.18.22","versionStartIncluding":"4.14","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.19.12","versionStartIncluding":"4.14","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.0","versionStartIncluding":"4.14","vulnerable":true}],"negate":false,"operator":"OR"}]}],"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nnetfilter: nf_conntrack_helper: pass helper to expect cleanup\n\nnf_conntrack_helper_unregister() calls nf_ct_expect_iterate_destroy()\nto remove expectations belonging to the helper being unregistered.\nHowever, it passes NULL instead of the helper pointer as the data\nargument, so expect_iter_me() never matches any expectation and all\nof them survive the cleanup.\n\nAfter unregister returns, nfnl_cthelper_del() frees the helper\nobject immediately.  Subsequent expectation dumps or packet-driven\ninit_conntrack() calls then dereference the freed exp->helper,\ncausing a use-after-free.\n\nPass the actual helper pointer so expectations referencing it are\nproperly destroyed before the helper object is freed.\n\n  BUG: KASAN: slab-use-after-free in string+0x38f/0x430\n  Read of size 1 at addr ffff888003b14d20 by task poc/103\n  Call Trace:\n   string+0x38f/0x430\n   vsnprintf+0x3cc/0x1170\n   seq_printf+0x17a/0x240\n   exp_seq_show+0x2e5/0x560\n   seq_read_iter+0x419/0x1280\n   proc_reg_read+0x1ac/0x270\n   vfs_read+0x179/0x930\n   ksys_read+0xef/0x1c0\n  Freed by task 103:\n  The buggy address is located 32 bytes inside of\n   freed 192-byte region [ffff888003b14d00, ffff888003b14dc0)"}],"providerMetadata":{"dateUpdated":"2026-05-01T14:15:28.521Z","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux"},"references":[{"url":"https://git.kernel.org/stable/c/5cf28d5c8dcbbe8af6d3b145babe491906d7bad1"},{"url":"https://git.kernel.org/stable/c/504ba4168466c91210c45acdc332479cfd5f2da6"},{"url":"https://git.kernel.org/stable/c/dc1739eff48e34cc71d4e2f03715493fbcebd8af"},{"url":"https://git.kernel.org/stable/c/2cf2737c85a2ba2b52024dafe68ffad2676f97be"},{"url":"https://git.kernel.org/stable/c/2c16e4d64dd91227742dfe196a3e7b0568bef65a"},{"url":"https://git.kernel.org/stable/c/620f3d14c1ef51d425060a3056ad8dbae8f998a3"},{"url":"https://git.kernel.org/stable/c/90bd7e8501349db3006d21fbc09df9ffcb172965"},{"url":"https://git.kernel.org/stable/c/a242a9ae58aa46ff7dae51ce64150a93957abe65"}],"title":"netfilter: nf_conntrack_helper: pass helper to expect cleanup","x_generator":{"engine":"bippy-1.2.0"}}},"cveMetadata":{"assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","assignerShortName":"Linux","cveId":"CVE-2026-43027","datePublished":"2026-05-01T14:15:28.521Z","dateReserved":"2026-05-01T14:12:55.976Z","dateUpdated":"2026-05-01T14:15:28.521Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-05-01 15:16:47","lastModifiedDate":"2026-05-01 15:24:14","problem_types":[],"metrics":[],"configurations":[]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"43027","Ordinal":"1","Title":"netfilter: nf_conntrack_helper: pass helper to expect cleanup","CVE":"CVE-2026-43027","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"43027","Ordinal":"1","NoteData":"In the Linux kernel, the following vulnerability has been resolved:\n\nnetfilter: nf_conntrack_helper: pass helper to expect cleanup\n\nnf_conntrack_helper_unregister() calls nf_ct_expect_iterate_destroy()\nto remove expectations belonging to the helper being unregistered.\nHowever, it passes NULL instead of the helper pointer as the data\nargument, so expect_iter_me() never matches any expectation and all\nof them survive the cleanup.\n\nAfter unregister returns, nfnl_cthelper_del() frees the helper\nobject immediately.  Subsequent expectation dumps or packet-driven\ninit_conntrack() calls then dereference the freed exp->helper,\ncausing a use-after-free.\n\nPass the actual helper pointer so expectations referencing it are\nproperly destroyed before the helper object is freed.\n\n  BUG: KASAN: slab-use-after-free in string+0x38f/0x430\n  Read of size 1 at addr ffff888003b14d20 by task poc/103\n  Call Trace:\n   string+0x38f/0x430\n   vsnprintf+0x3cc/0x1170\n   seq_printf+0x17a/0x240\n   exp_seq_show+0x2e5/0x560\n   seq_read_iter+0x419/0x1280\n   proc_reg_read+0x1ac/0x270\n   vfs_read+0x179/0x930\n   ksys_read+0xef/0x1c0\n  Freed by task 103:\n  The buggy address is located 32 bytes inside of\n   freed 192-byte region [ffff888003b14d00, ffff888003b14dc0)","Type":"Description","Title":"netfilter: nf_conntrack_helper: pass helper to expect cleanup"}]}}}