CVE-2026-64554

HIGHPre-NVD 8.88.8—
EchelonGraph scoreMEDIUM confidence

Score 8.8 from GitHub Security Advisory (severity: HIGH) published 2026-07-27. a secondary CVSS source baseline 8.8; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, secondary
Trending — 3 sources updated this week
8.8EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 8.8Exploit: None knownExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

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

CVSS v3
8.8
EG Score
8.8(medium)
EG Risk
44(Track)
EG Risk 44/100SSVC: Track

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity88% × 45%
Exploitation0% × 40%
Automatability30% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
17%
KEV
Not listed

Published

July 27, 2026

Last Modified

August 17, 2026

Advisory Details (8)

Auto-updated Jul 30, 2026
No patch confirmed yet.
generic

netfilter: bridge: fix stale prevhdr pointer in br_ip6_fragment() - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/86f3ce81dd2b4b0aa2c3016c989a943e4b1b643d
generic

netfilter: bridge: fix stale prevhdr pointer in br_ip6_fragment() - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/4ac981a8b7ce7aec99a52d08f8a8953e8e120067
generic

netfilter: bridge: fix stale prevhdr pointer in br_ip6_fragment() - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/1c4f67c89fd27c4df4c70b135c2c59627698b3c0
generic

netfilter: bridge: fix stale prevhdr pointer in br_ip6_fragment() - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/f2e6596d10783557aeb9668da2a3b4d19deb2001
generic

netfilter: bridge: fix stale prevhdr pointer in br_ip6_fragment() - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/c141f69d0a0fb16964dbc293650047e69bda8af7
generic

netfilter: bridge: fix stale prevhdr pointer in br_ip6_fragment() - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/00c06ef8c018493943891a7d0ca82b71b24f3180
generic

netfilter: bridge: fix stale prevhdr pointer in br_ip6_fragment() - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/2731efa6364e47934c96eb69e01ea131e8af8030
generic

netfilter: bridge: fix stale prevhdr pointer in br_ip6_fragment() - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/8c10778ec674b67a07ea042fcba64270f3f38a5a

Vendor Advisories for CVE-2026-64554(1)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Affected Packages

(6 across 4 ecosystems)
Debian:11(2)
PackageVulnerable rangeFixed inDependents
linux5.10.103-1 ... 5.10.92-2 (55 versions)5.10.262-1—
linux-6.16.1.106-3~deb11u1 ... 6.1.177-1~deb11u1 (22 versions)6.1.180-1~deb11u1—
Debian:12(2)
PackageVulnerable rangeFixed inDependents
linux6.1.106-1 ... 6.1.99-1 (55 versions)6.1.180-1—
linux-6.12—6.12.100-1~deb12u1—
Debian:13(1)
PackageVulnerable rangeFixed inDependents
linux6.12.38-1 ... 6.12.96-1 (31 versions)6.12.100-1—
Debian:14(1)
PackageVulnerable rangeFixed inDependents
linux6.12.100-1 ... 7.1~rc7-1~exp1 (157 versions)7.1.5-1—

Data Freshness Timeline

(refreshed 20× in last 7d / 111× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

Showing the most recent 100 of 127 total refreshes for this CVE.

  1. 2026-08-30 01:22 UTCEPSS rescore
  2. 2026-08-29 23:48 UTCEG score recompute
  3. 2026-08-29 23:48 UTCGHSA enrichment
  4. 2026-08-28 21:42 UTCEPSS rescore
  5. 2026-08-27 22:09 UTCEG score recompute
  6. 2026-08-27 22:09 UTCGHSA enrichment
  7. 2026-08-27 09:42 UTCEG score recompute
  8. 2026-08-27 09:42 UTCGHSA enrichment
  9. 2026-08-26 19:44 UTCEG score recompute
  10. 2026-08-26 19:44 UTCGHSA enrichment
  11. 2026-08-26 14:47 UTCEPSS rescore
  12. 2026-08-26 04:27 UTCGHSA enrichment
  13. 2026-08-25 15:49 UTCEG score recompute
  14. 2026-08-25 15:49 UTCGHSA enrichment
  15. 2026-08-25 13:49 UTCEPSS rescore
  16. 2026-08-25 03:21 UTCGHSA enrichment
  17. 2026-08-24 14:54 UTCEG score recompute
  18. 2026-08-24 14:54 UTCGHSA enrichment
  19. 2026-08-24 02:25 UTCGHSA enrichment
  20. 2026-08-23 13:54 UTCGHSA enrichment
  21. 2026-08-23 01:26 UTCEG score recompute
  22. 2026-08-23 01:26 UTCGHSA enrichment
  23. 2026-08-23 00:19 UTCEPSS rescore
  24. 2026-08-22 12:59 UTCGHSA enrichment
  25. 2026-08-22 00:31 UTCEG score recompute
Show 75 more
  1. 2026-08-22 00:31 UTCGHSA enrichment
  2. 2026-08-21 23:49 UTCEPSS rescore
  3. 2026-08-21 12:03 UTCGHSA enrichment
  4. 2026-08-20 23:35 UTCEG score recompute
  5. 2026-08-20 23:35 UTCGHSA enrichment
  6. 2026-08-20 22:55 UTCEPSS rescore
  7. 2026-08-20 11:08 UTCGHSA enrichment
  8. 2026-08-19 22:41 UTCEG score recompute
  9. 2026-08-19 22:41 UTCGHSA enrichment
  10. 2026-08-19 17:04 UTCEPSS rescore
  11. 2026-08-19 10:13 UTCGHSA enrichment
  12. 2026-08-18 21:46 UTCEG score recompute
  13. 2026-08-18 21:46 UTCGHSA enrichment
  14. 2026-08-18 13:48 UTCEPSS rescore
  15. 2026-08-18 08:48 UTCGHSA enrichment
  16. 2026-08-17 20:15 UTCEG score recompute
  17. 2026-08-17 20:15 UTCGHSA enrichment
  18. 2026-08-17 13:47 UTCEPSS rescore
  19. 2026-08-17 05:42 UTCEG score recompute
  20. 2026-08-17 05:42 UTCGHSA enrichment
  21. 2026-08-17 05:14 UTCGHSA enrichment
  22. 2026-08-16 23:32 UTCEG score recompute
  23. 2026-08-16 23:32 UTCGHSA enrichment
  24. 2026-08-16 14:56 UTCEPSS rescore
  25. 2026-08-16 11:04 UTCEG score recompute
  26. 2026-08-16 11:04 UTCGHSA enrichment
  27. 2026-08-15 22:37 UTCGHSA enrichment
  28. 2026-08-15 10:09 UTCEG score recompute
  29. 2026-08-15 10:09 UTCGHSA enrichment
  30. 2026-08-15 01:30 UTCEPSS rescore
  31. 2026-08-14 21:41 UTCGHSA enrichment
  32. 2026-08-14 09:14 UTCEG score recompute
  33. 2026-08-14 09:14 UTCGHSA enrichment
  34. 2026-08-13 22:00 UTCEPSS rescore
  35. 2026-08-13 20:46 UTCGHSA enrichment
  36. 2026-08-13 08:18 UTCGHSA enrichment
  37. 2026-08-12 19:51 UTCEG score recompute
  38. 2026-08-12 19:51 UTCGHSA enrichment
  39. 2026-08-12 13:51 UTCEPSS rescore
  40. 2026-08-12 07:24 UTCGHSA enrichment
  41. 2026-08-11 18:56 UTCEG score recompute
  42. 2026-08-11 18:56 UTCGHSA enrichment
  43. 2026-08-11 06:28 UTCEG score recompute
  44. 2026-08-11 06:28 UTCGHSA enrichment
  45. 2026-08-11 00:00 UTCEPSS rescore
  46. 2026-08-10 18:01 UTCGHSA enrichment
  47. 2026-08-10 05:18 UTCGHSA enrichment
  48. 2026-08-09 16:50 UTCEG score recompute
  49. 2026-08-09 16:50 UTCGHSA enrichment
  50. 2026-08-09 13:47 UTCEPSS rescore
  51. 2026-08-09 04:23 UTCEG score recompute
  52. 2026-08-09 04:23 UTCGHSA enrichment
  53. 2026-08-08 16:37 UTCEPSS rescore
  54. 2026-08-08 15:56 UTCGHSA enrichment
  55. 2026-08-08 03:28 UTCEG score recompute
  56. 2026-08-08 03:28 UTCGHSA enrichment
  57. 2026-08-07 15:00 UTCGHSA enrichment
  58. 2026-08-07 02:32 UTCGHSA enrichment
  59. 2026-08-06 14:05 UTCEG score recompute
  60. 2026-08-06 14:05 UTCGHSA enrichment
  61. 2026-08-06 13:47 UTCEPSS rescore
  62. 2026-08-06 01:37 UTCEG score recompute
  63. 2026-08-06 01:37 UTCGHSA enrichment
  64. 2026-08-05 19:17 UTCEPSS rescore
  65. 2026-08-05 19:17 UTCEPSS rescore
  66. 2026-08-05 13:10 UTCEG score recompute
  67. 2026-08-05 13:10 UTCGHSA enrichment
  68. 2026-08-05 01:09 UTCEG score recompute
  69. 2026-08-05 01:08 UTCGHSA enrichment
  70. 2026-08-04 15:10 UTCEPSS rescore
  71. 2026-08-04 12:37 UTCEG score recompute
  72. 2026-08-04 12:37 UTCGHSA enrichment
  73. 2026-08-04 10:39 UTCEPSS rescore
  74. 2026-08-03 23:05 UTCGHSA enrichment
  75. 2026-08-03 10:37 UTCEG score recompute

Frequently asked(5)

What is CVE-2026-64554?
CVE-2026-64554 is a high vulnerability published on July 27, 2026. In the Linux kernel, the following vulnerability has been resolved: netfilter: bridge: fix stale prevhdr pointer in brip6fragment() brip6fragment() gets prevhdr, a pointer into the skb head, from ip6find1stfragopt(), then calls skbchecksumhelp(). For a cloned skb skbchecksumhelp() reallocates the…
When was CVE-2026-64554 disclosed?
CVE-2026-64554 was first published in the National Vulnerability Database on July 27, 2026, with the most recent update on August 17, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-64554 actively exploited?
CVE-2026-64554 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0% probability of exploitation in the next 30 days, which ranks it in the top 83.2% of all scored CVEs.
What is the CVSS score of CVE-2026-64554?
CVE-2026-64554 has a CVSS v3 base score of 8.8 (NVD).
How do I remediate CVE-2026-64554?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-64554, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

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