{"api_version":"1","generated_at":"2026-07-28T01:58:12+00:00","cve":"CVE-2026-64554","urls":{"html":"https://cve.report/CVE-2026-64554","api":"https://cve.report/api/cve/CVE-2026-64554.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-64554","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-64554"},"summary":{"title":"netfilter: bridge: fix stale prevhdr pointer in br_ip6_fragment()","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nnetfilter: bridge: fix stale prevhdr pointer in br_ip6_fragment()\n\nbr_ip6_fragment() gets prevhdr, a pointer into the skb head, from\nip6_find_1stfragopt(), then calls skb_checksum_help().  For a cloned skb\nskb_checksum_help() reallocates the head via pskb_expand_head(), leaving\nprevhdr dangling.  It is later dereferenced in ip6_frag_next(), causing a\nuse-after-free write.\n\nSave prevhdr's offset before skb_checksum_help() and recompute it after,\nlike commit ef0efcd3bd3f (\"ipv6: Fix dangling pointer when ipv6\nfragment\").\n\n  BUG: KASAN: slab-use-after-free in ip6_frag_next (net/ipv6/ip6_output.c:857)\n  Write of size 1 at addr ffff888013ff5016 by task exploit/141\n  Call Trace:\n   ...\n   kasan_report (mm/kasan/report.c:595)\n   ip6_frag_next (net/ipv6/ip6_output.c:857)\n   br_ip6_fragment (net/ipv6/netfilter.c:212)\n   nf_ct_bridge_post (net/bridge/netfilter/nf_conntrack_bridge.c:407)\n   nf_hook_slow (net/netfilter/core.c:619)\n   br_forward_finish (net/bridge/br_forward.c:66)\n   __br_forward (net/bridge/br_forward.c:115)\n   maybe_deliver (net/bridge/br_forward.c:191)\n   br_flood (net/bridge/br_forward.c:245)\n   br_handle_frame_finish (net/bridge/br_input.c:229)\n   br_handle_frame (net/bridge/br_input.c:442)\n   ...\n   packet_sendmsg (net/packet/af_packet.c:3114)\n   ...\n   do_syscall_64 (arch/x86/entry/syscall_64.c:94)\n   entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:121)\n  Kernel panic - not syncing: Fatal exception in interrupt","state":"PUBLISHED","assigner":"Linux","published_at":"2026-07-27 21:17:08","updated_at":"2026-07-27 21:17:08"},"problem_types":[],"metrics":[],"references":[{"url":"https://git.kernel.org/stable/c/1c4f67c89fd27c4df4c70b135c2c59627698b3c0","name":"https://git.kernel.org/stable/c/1c4f67c89fd27c4df4c70b135c2c59627698b3c0","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/2731efa6364e47934c96eb69e01ea131e8af8030","name":"https://git.kernel.org/stable/c/2731efa6364e47934c96eb69e01ea131e8af8030","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/8c10778ec674b67a07ea042fcba64270f3f38a5a","name":"https://git.kernel.org/stable/c/8c10778ec674b67a07ea042fcba64270f3f38a5a","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/86f3ce81dd2b4b0aa2c3016c989a943e4b1b643d","name":"https://git.kernel.org/stable/c/86f3ce81dd2b4b0aa2c3016c989a943e4b1b643d","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/c141f69d0a0fb16964dbc293650047e69bda8af7","name":"https://git.kernel.org/stable/c/c141f69d0a0fb16964dbc293650047e69bda8af7","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/00c06ef8c018493943891a7d0ca82b71b24f3180","name":"https://git.kernel.org/stable/c/00c06ef8c018493943891a7d0ca82b71b24f3180","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/4ac981a8b7ce7aec99a52d08f8a8953e8e120067","name":"https://git.kernel.org/stable/c/4ac981a8b7ce7aec99a52d08f8a8953e8e120067","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/f2e6596d10783557aeb9668da2a3b4d19deb2001","name":"https://git.kernel.org/stable/c/f2e6596d10783557aeb9668da2a3b4d19deb2001","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-64554","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-64554","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 764dd163ac922f8683b5bcd3007251ce7b26cd33 8c10778ec674b67a07ea042fcba64270f3f38a5a git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 764dd163ac922f8683b5bcd3007251ce7b26cd33 2731efa6364e47934c96eb69e01ea131e8af8030 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 764dd163ac922f8683b5bcd3007251ce7b26cd33 00c06ef8c018493943891a7d0ca82b71b24f3180 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 764dd163ac922f8683b5bcd3007251ce7b26cd33 c141f69d0a0fb16964dbc293650047e69bda8af7 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 764dd163ac922f8683b5bcd3007251ce7b26cd33 f2e6596d10783557aeb9668da2a3b4d19deb2001 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 764dd163ac922f8683b5bcd3007251ce7b26cd33 1c4f67c89fd27c4df4c70b135c2c59627698b3c0 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 764dd163ac922f8683b5bcd3007251ce7b26cd33 4ac981a8b7ce7aec99a52d08f8a8953e8e120067 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 764dd163ac922f8683b5bcd3007251ce7b26cd33 86f3ce81dd2b4b0aa2c3016c989a943e4b1b643d git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 5.3","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 5.3 semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 5.10.261 5.10.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 5.15.212 5.15.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.1.178 6.1.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.6.145 6.6.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.12.97 6.12.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.18.40 6.18.* 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-rc4 * 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/ipv6/netfilter.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"lessThan":"8c10778ec674b67a07ea042fcba64270f3f38a5a","status":"affected","version":"764dd163ac922f8683b5bcd3007251ce7b26cd33","versionType":"git"},{"lessThan":"2731efa6364e47934c96eb69e01ea131e8af8030","status":"affected","version":"764dd163ac922f8683b5bcd3007251ce7b26cd33","versionType":"git"},{"lessThan":"00c06ef8c018493943891a7d0ca82b71b24f3180","status":"affected","version":"764dd163ac922f8683b5bcd3007251ce7b26cd33","versionType":"git"},{"lessThan":"c141f69d0a0fb16964dbc293650047e69bda8af7","status":"affected","version":"764dd163ac922f8683b5bcd3007251ce7b26cd33","versionType":"git"},{"lessThan":"f2e6596d10783557aeb9668da2a3b4d19deb2001","status":"affected","version":"764dd163ac922f8683b5bcd3007251ce7b26cd33","versionType":"git"},{"lessThan":"1c4f67c89fd27c4df4c70b135c2c59627698b3c0","status":"affected","version":"764dd163ac922f8683b5bcd3007251ce7b26cd33","versionType":"git"},{"lessThan":"4ac981a8b7ce7aec99a52d08f8a8953e8e120067","status":"affected","version":"764dd163ac922f8683b5bcd3007251ce7b26cd33","versionType":"git"},{"lessThan":"86f3ce81dd2b4b0aa2c3016c989a943e4b1b643d","status":"affected","version":"764dd163ac922f8683b5bcd3007251ce7b26cd33","versionType":"git"}]},{"defaultStatus":"affected","product":"Linux","programFiles":["net/ipv6/netfilter.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"status":"affected","version":"5.3"},{"lessThan":"5.3","status":"unaffected","version":"0","versionType":"semver"},{"lessThanOrEqual":"5.10.*","status":"unaffected","version":"5.10.261","versionType":"semver"},{"lessThanOrEqual":"5.15.*","status":"unaffected","version":"5.15.212","versionType":"semver"},{"lessThanOrEqual":"6.1.*","status":"unaffected","version":"6.1.178","versionType":"semver"},{"lessThanOrEqual":"6.6.*","status":"unaffected","version":"6.6.145","versionType":"semver"},{"lessThanOrEqual":"6.12.*","status":"unaffected","version":"6.12.97","versionType":"semver"},{"lessThanOrEqual":"6.18.*","status":"unaffected","version":"6.18.40","versionType":"semver"},{"lessThanOrEqual":"7.1.*","status":"unaffected","version":"7.1.5","versionType":"semver"},{"lessThanOrEqual":"*","status":"unaffected","version":"7.2-rc4","versionType":"original_commit_for_fix"}]}],"cpeApplicability":[{"nodes":[{"cpeMatch":[{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"5.10.261","versionStartIncluding":"5.3","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"5.15.212","versionStartIncluding":"5.3","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.1.178","versionStartIncluding":"5.3","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.6.145","versionStartIncluding":"5.3","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.12.97","versionStartIncluding":"5.3","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.18.40","versionStartIncluding":"5.3","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.1.5","versionStartIncluding":"5.3","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.2-rc4","versionStartIncluding":"5.3","vulnerable":true}],"negate":false,"operator":"OR"}]}],"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nnetfilter: bridge: fix stale prevhdr pointer in br_ip6_fragment()\n\nbr_ip6_fragment() gets prevhdr, a pointer into the skb head, from\nip6_find_1stfragopt(), then calls skb_checksum_help().  For a cloned skb\nskb_checksum_help() reallocates the head via pskb_expand_head(), leaving\nprevhdr dangling.  It is later dereferenced in ip6_frag_next(), causing a\nuse-after-free write.\n\nSave prevhdr's offset before skb_checksum_help() and recompute it after,\nlike commit ef0efcd3bd3f (\"ipv6: Fix dangling pointer when ipv6\nfragment\").\n\n  BUG: KASAN: slab-use-after-free in ip6_frag_next (net/ipv6/ip6_output.c:857)\n  Write of size 1 at addr ffff888013ff5016 by task exploit/141\n  Call Trace:\n   ...\n   kasan_report (mm/kasan/report.c:595)\n   ip6_frag_next (net/ipv6/ip6_output.c:857)\n   br_ip6_fragment (net/ipv6/netfilter.c:212)\n   nf_ct_bridge_post (net/bridge/netfilter/nf_conntrack_bridge.c:407)\n   nf_hook_slow (net/netfilter/core.c:619)\n   br_forward_finish (net/bridge/br_forward.c:66)\n   __br_forward (net/bridge/br_forward.c:115)\n   maybe_deliver (net/bridge/br_forward.c:191)\n   br_flood (net/bridge/br_forward.c:245)\n   br_handle_frame_finish (net/bridge/br_input.c:229)\n   br_handle_frame (net/bridge/br_input.c:442)\n   ...\n   packet_sendmsg (net/packet/af_packet.c:3114)\n   ...\n   do_syscall_64 (arch/x86/entry/syscall_64.c:94)\n   entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:121)\n  Kernel panic - not syncing: Fatal exception in interrupt"}],"providerMetadata":{"dateUpdated":"2026-07-27T20:10:41.726Z","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux"},"references":[{"url":"https://git.kernel.org/stable/c/8c10778ec674b67a07ea042fcba64270f3f38a5a"},{"url":"https://git.kernel.org/stable/c/2731efa6364e47934c96eb69e01ea131e8af8030"},{"url":"https://git.kernel.org/stable/c/00c06ef8c018493943891a7d0ca82b71b24f3180"},{"url":"https://git.kernel.org/stable/c/c141f69d0a0fb16964dbc293650047e69bda8af7"},{"url":"https://git.kernel.org/stable/c/f2e6596d10783557aeb9668da2a3b4d19deb2001"},{"url":"https://git.kernel.org/stable/c/1c4f67c89fd27c4df4c70b135c2c59627698b3c0"},{"url":"https://git.kernel.org/stable/c/4ac981a8b7ce7aec99a52d08f8a8953e8e120067"},{"url":"https://git.kernel.org/stable/c/86f3ce81dd2b4b0aa2c3016c989a943e4b1b643d"}],"title":"netfilter: bridge: fix stale prevhdr pointer in br_ip6_fragment()","x_generator":{"engine":"bippy-1.2.0"}}},"cveMetadata":{"assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","assignerShortName":"Linux","cveId":"CVE-2026-64554","datePublished":"2026-07-27T20:10:41.726Z","dateReserved":"2026-07-19T15:36:31.796Z","dateUpdated":"2026-07-27T20:10:41.726Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-07-27 21:17:08","lastModifiedDate":"2026-07-27 21:17:08","problem_types":[],"metrics":[],"configurations":[]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"64554","Ordinal":"1","Title":"netfilter: bridge: fix stale prevhdr pointer in br_ip6_fragment(","CVE":"CVE-2026-64554","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"64554","Ordinal":"1","NoteData":"In the Linux kernel, the following vulnerability has been resolved:\n\nnetfilter: bridge: fix stale prevhdr pointer in br_ip6_fragment()\n\nbr_ip6_fragment() gets prevhdr, a pointer into the skb head, from\nip6_find_1stfragopt(), then calls skb_checksum_help().  For a cloned skb\nskb_checksum_help() reallocates the head via pskb_expand_head(), leaving\nprevhdr dangling.  It is later dereferenced in ip6_frag_next(), causing a\nuse-after-free write.\n\nSave prevhdr's offset before skb_checksum_help() and recompute it after,\nlike commit ef0efcd3bd3f (\"ipv6: Fix dangling pointer when ipv6\nfragment\").\n\n  BUG: KASAN: slab-use-after-free in ip6_frag_next (net/ipv6/ip6_output.c:857)\n  Write of size 1 at addr ffff888013ff5016 by task exploit/141\n  Call Trace:\n   ...\n   kasan_report (mm/kasan/report.c:595)\n   ip6_frag_next (net/ipv6/ip6_output.c:857)\n   br_ip6_fragment (net/ipv6/netfilter.c:212)\n   nf_ct_bridge_post (net/bridge/netfilter/nf_conntrack_bridge.c:407)\n   nf_hook_slow (net/netfilter/core.c:619)\n   br_forward_finish (net/bridge/br_forward.c:66)\n   __br_forward (net/bridge/br_forward.c:115)\n   maybe_deliver (net/bridge/br_forward.c:191)\n   br_flood (net/bridge/br_forward.c:245)\n   br_handle_frame_finish (net/bridge/br_input.c:229)\n   br_handle_frame (net/bridge/br_input.c:442)\n   ...\n   packet_sendmsg (net/packet/af_packet.c:3114)\n   ...\n   do_syscall_64 (arch/x86/entry/syscall_64.c:94)\n   entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:121)\n  Kernel panic - not syncing: Fatal exception in interrupt","Type":"Description","Title":"netfilter: bridge: fix stale prevhdr pointer in br_ip6_fragment("}]}}}