Answer in brief
CVE-2026-64554 records a Unknown severity vulnerability in netfilter: bridge: fix stale prevhdr pointer in br_ip6_fragment(). The current sources do not mark it as known exploited. The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
Answer in brief
CVE-2026-64554 records a Unknown severity vulnerability in netfilter: bridge: fix stale prevhdr pointer in br_ip6_fragment(). The current sources do not mark it as known exploited. The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
A CVSS score is not reported in the current record. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| Linux/Linuxgeneric | >=764dd163ac922f8683b5bcd3007251ce7b26cd33 <8c10778ec674b67a07ea042fcba64270f3f38a5a || >=764dd163ac922f8683b5bcd3007251ce7b26cd33 <2731efa6364e47934c96eb69e01ea131e8af8030 || >=764dd163ac922f8683b5bcd3007251ce7b26cd33 <00c06ef8c018493943891a7d0ca82b71b24f3180 || >=764dd163ac922f8683b5bcd3007251ce7b26cd33 <c141f69d0a0fb16964dbc293650047e69bda8af7 || >=764dd163ac922f8683b5bcd3007251ce7b26cd33 <f2e6596d10783557aeb9668da2a3b4d19deb2001 || >=764dd163ac922f8683b5bcd3007251ce7b26cd33 <1c4f67c89fd27c4df4c70b135c2c59627698b3c0 || >=764dd163ac922f8683b5bcd3007251ce7b26cd33 <4ac981a8b7ce7aec99a52d08f8a8953e8e120067 || >=764dd163ac922f8683b5bcd3007251ce7b26cd33 <86f3ce81dd2b4b0aa2c3016c989a943e4b1b643d | 8c10778ec674b67a07ea042fcba64270f3f38a5a, 2731efa6364e47934c96eb69e01ea131e8af8030, 00c06ef8c018493943891a7d0ca82b71b24f3180, c141f69d0a0fb16964dbc293650047e69bda8af7, f2e6596d10783557aeb9668da2a3b4d19deb2001, 1c4f67c89fd27c4df4c70b135c2c59627698b3c0, 4ac981a8b7ce7aec99a52d08f8a8953e8e120067, 86f3ce81dd2b4b0aa2c3016c989a943e4b1b643d |
| Linux/Linuxgeneric | 5.3 | Not reported |
Published upstream
Jul 27, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Aug 5, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Aug 5, 2026
In the Linux kernel, the following vulnerability has been resolved: netfilter: bridge: fix stale prevhdr pointer in br_ip6_fragment() br_ip6_fragment() gets prevhdr, a pointer into the skb head, from ip6_find_1stfragopt(), then calls skb_checksum_help(). For a cloned skb skb_checksum_help() reallocates the head via pskb_expand_head(), leaving prevhdr dangling. It is later dereferenced in ip6_frag_next(), causing a use-after-free write. Save prevhdr's offset before skb_checksum_help() and recompute it after, like commit ef0efcd3bd3f ("ipv6: Fix dangling pointer when ipv6 fragment"). BUG: KASAN: slab-use-after-free in ip6_frag_next (net/ipv6/ip6_output.c:857) Write of size 1 at addr ffff888013ff5016 by task exploit/141 Call Trace: ... kasan_report (mm/kasan/report.c:595) ip6_frag_next (net/ipv6/ip6_output.c:857) br_ip6_fragment (net/ipv6/netfilter.c:212) nf_ct_bridge_post (net/bridge/netfilter/nf_conntrack_bridge.c:407) nf_hook_slow (net/netfilter/core.c:619) br_forward_finish (net/bridge/br_forward.c:66) __br_forward (net/bridge/br_forward.c:115) maybe_deliver (net/bridge/br_forward.c:191) br_flood (net/bridge/br_forward.c:245) br_handle_frame_finish (net/bridge/br_input.c:229) br_handle_frame (net/bridge/br_input.c:442) ... packet_sendmsg (net/packet/af_packet.c:3114) ... do_syscall_64 (arch/x86/entry/syscall_64.c:94) entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:121) Kernel panic - not syncing: Fatal exception in interrupt
Quoted source text, attributed separately from HOL analysis.
A CVSS score is not reported in the current record. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| Linux/Linuxgeneric | >=764dd163ac922f8683b5bcd3007251ce7b26cd33 <8c10778ec674b67a07ea042fcba64270f3f38a5a || >=764dd163ac922f8683b5bcd3007251ce7b26cd33 <2731efa6364e47934c96eb69e01ea131e8af8030 || >=764dd163ac922f8683b5bcd3007251ce7b26cd33 <00c06ef8c018493943891a7d0ca82b71b24f3180 || >=764dd163ac922f8683b5bcd3007251ce7b26cd33 <c141f69d0a0fb16964dbc293650047e69bda8af7 || >=764dd163ac922f8683b5bcd3007251ce7b26cd33 <f2e6596d10783557aeb9668da2a3b4d19deb2001 || >=764dd163ac922f8683b5bcd3007251ce7b26cd33 <1c4f67c89fd27c4df4c70b135c2c59627698b3c0 || >=764dd163ac922f8683b5bcd3007251ce7b26cd33 <4ac981a8b7ce7aec99a52d08f8a8953e8e120067 || >=764dd163ac922f8683b5bcd3007251ce7b26cd33 <86f3ce81dd2b4b0aa2c3016c989a943e4b1b643d | 8c10778ec674b67a07ea042fcba64270f3f38a5a, 2731efa6364e47934c96eb69e01ea131e8af8030, 00c06ef8c018493943891a7d0ca82b71b24f3180, c141f69d0a0fb16964dbc293650047e69bda8af7, f2e6596d10783557aeb9668da2a3b4d19deb2001, 1c4f67c89fd27c4df4c70b135c2c59627698b3c0, 4ac981a8b7ce7aec99a52d08f8a8953e8e120067, 86f3ce81dd2b4b0aa2c3016c989a943e4b1b643d |
| Linux/Linuxgeneric | 5.3 | Not reported |
Published upstream
Jul 27, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Aug 5, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Aug 5, 2026
In the Linux kernel, the following vulnerability has been resolved: netfilter: bridge: fix stale prevhdr pointer in br_ip6_fragment() br_ip6_fragment() gets prevhdr, a pointer into the skb head, from ip6_find_1stfragopt(), then calls skb_checksum_help(). For a cloned skb skb_checksum_help() reallocates the head via pskb_expand_head(), leaving prevhdr dangling. It is later dereferenced in ip6_frag_next(), causing a use-after-free write. Save prevhdr's offset before skb_checksum_help() and recompute it after, like commit ef0efcd3bd3f ("ipv6: Fix dangling pointer when ipv6 fragment"). BUG: KASAN: slab-use-after-free in ip6_frag_next (net/ipv6/ip6_output.c:857) Write of size 1 at addr ffff888013ff5016 by task exploit/141 Call Trace: ... kasan_report (mm/kasan/report.c:595) ip6_frag_next (net/ipv6/ip6_output.c:857) br_ip6_fragment (net/ipv6/netfilter.c:212) nf_ct_bridge_post (net/bridge/netfilter/nf_conntrack_bridge.c:407) nf_hook_slow (net/netfilter/core.c:619) br_forward_finish (net/bridge/br_forward.c:66) __br_forward (net/bridge/br_forward.c:115) maybe_deliver (net/bridge/br_forward.c:191) br_flood (net/bridge/br_forward.c:245) br_handle_frame_finish (net/bridge/br_input.c:229) br_handle_frame (net/bridge/br_input.c:442) ... packet_sendmsg (net/packet/af_packet.c:3114) ... do_syscall_64 (arch/x86/entry/syscall_64.c:94) entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:121) Kernel panic - not syncing: Fatal exception in interrupt
Quoted source text, attributed separately from HOL analysis.