{"id":"CVE-2026-64554","revision":"1bb0cb27810f42cabebcdfccef5a29c8","records":[{"revision":"1bb0cb27810f42cabebcdfccef5a29c8","observedAt":"2026-10-23T15:48:27.903+00:00","statement":{"source":"cve-program","id":"CVE-2026-64554","aliases":[],"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":0,"publishedAt":"2026-07-27T20:10:41.726+00:00","modifiedAt":"2026-10-19T20:48:40.742+00:00","affected":[{"ecosystem":"Vendor product","name":"Linux","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"product\": \"Linux\",\n                    \"vendor\": \"Linux\",\n                    \"defaultStatus\": \"unaffected\",\n                    \"repo\": \"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\n                    \"programFiles\": [\n                        \"net/ipv6/netfilter.c\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"764dd163ac922f8683b5bcd3007251ce7b26cd33\",\n                            \"lessThan\": \"8c10778ec674b67a07ea042fcba64270f3f38a5a\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"764dd163ac922f8683b5bcd3007251ce7b26cd33\",\n                            \"lessThan\": \"2731efa6364e47934c96eb69e01ea131e8af8030\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"764dd163ac922f8683b5bcd3007251ce7b26cd33\",\n                            \"lessThan\": \"00c06ef8c018493943891a7d0ca82b71b24f3180\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"764dd163ac922f8683b5bcd3007251ce7b26cd33\",\n                            \"lessThan\": \"c141f69d0a0fb16964dbc293650047e69bda8af7\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"764dd163ac922f8683b5bcd3007251ce7b26cd33\",\n                            \"lessThan\": \"f2e6596d10783557aeb9668da2a3b4d19deb2001\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"764dd163ac922f8683b5bcd3007251ce7b26cd33\",\n                            \"lessThan\": \"1c4f67c89fd27c4df4c70b135c2c59627698b3c0\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"764dd163ac922f8683b5bcd3007251ce7b26cd33\",\n                            \"lessThan\": \"4ac981a8b7ce7aec99a52d08f8a8953e8e120067\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"764dd163ac922f8683b5bcd3007251ce7b26cd33\",\n                            \"lessThan\": \"86f3ce81dd2b4b0aa2c3016c989a943e4b1b643d\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        }\n                    ]\n                }"},{"ecosystem":"Vendor product","name":"Linux","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"product\": \"Linux\",\n                    \"vendor\": \"Linux\",\n                    \"defaultStatus\": \"affected\",\n                    \"repo\": \"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\n                    \"programFiles\": [\n                        \"net/ipv6/netfilter.c\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"5.3\",\n                            \"status\": \"affected\"\n                        },\n                        {\n                            \"version\": \"0\",\n                            \"lessThan\": \"5.3\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"5.10.261\",\n                            \"lessThanOrEqual\": \"5.10.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"5.15.212\",\n                            \"lessThanOrEqual\": \"5.15.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.1.178\",\n                            \"lessThanOrEqual\": \"6.1.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.6.145\",\n                            \"lessThanOrEqual\": \"6.6.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.12.97\",\n                            \"lessThanOrEqual\": \"6.12.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.18.40\",\n                            \"lessThanOrEqual\": \"6.18.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"7.1.5\",\n                            \"lessThanOrEqual\": \"7.1.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"7.2\",\n                            \"lessThanOrEqual\": \"*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"original_commit_for_fix\"\n                        }\n                    ]\n                }"}],"metrics":[{"system":"CVSS 3.1","vector":"CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","score":8.8,"severity":"HIGH"}],"references":["https://git.kernel.org/stable/c/8c10778ec674b67a07ea042fcba64270f3f38a5a","https://git.kernel.org/stable/c/2731efa6364e47934c96eb69e01ea131e8af8030","https://git.kernel.org/stable/c/00c06ef8c018493943891a7d0ca82b71b24f3180","https://git.kernel.org/stable/c/c141f69d0a0fb16964dbc293650047e69bda8af7","https://git.kernel.org/stable/c/f2e6596d10783557aeb9668da2a3b4d19deb2001","https://git.kernel.org/stable/c/1c4f67c89fd27c4df4c70b135c2c59627698b3c0","https://git.kernel.org/stable/c/4ac981a8b7ce7aec99a52d08f8a8953e8e120067","https://git.kernel.org/stable/c/86f3ce81dd2b4b0aa2c3016c989a943e4b1b643d"],"sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-64554","license":"CVE Program Terms of Use","key":"cve-program:CVE-2026-64554","identifiers":["CVE-2026-64554"]},"retained":false,"historicalAffected":[]}],"coverage":[]}