CVE-2026-63796

HIGHPre-NVD 8.88.8—
EchelonGraph scoreMEDIUM confidence

Score 8.8 from GitHub Security Advisory (severity: HIGH) published 2026-07-19. a secondary CVSS source baseline 8.8; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, secondary
Trending — 4 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:

ocfs2: reject oversized group bitmap descriptors

ocfs2_validate_gd_parent() only bounds bg_bits against the parent allocator's chain geometry. A malicious descriptor can still claim a bg_size/bg_bits pair that exceeds the bitmap bytes that physically fit in the group descriptor block, so later bitmap scans and bit updates can run past bg_bitmap.

Add a physical-cap check based on ocfs2_group_bitmap_size() for the parent allocator type and reject descriptors whose bg_size or bg_bits exceed that capacity. Keep the existing chain geometry check so both the on-disk bitmap layout and the allocator metadata must agree before the descriptor is used.

Validation reproduced this kernel report: KASAN use-after-free in _find_next_bit+0x7f/0xc0 Read of size 8 Call trace: dump_stack_lvl+0x66/0xa0 (?:?) print_report+0xd0/0x630 (?:?) _find_next_bit+0x7f/0xc0 (?:?) srso_alias_return_thunk+0x5/0xfbef5 (?:?) __virt_addr_valid+0x188/0x2f0 (?:?) kasan_report+0xe4/0x120 (?:?) ocfs2_find_max_contig_free_bits+0x35/0x70 (fs/ocfs2/suballoc.c:1375) ocfs2_block_group_set_bits+0x472/0x4b0 (fs/ocfs2/suballoc.c:1457) ocfs2_cluster_group_search+0x16b/0x440 (fs/ocfs2/suballoc.c:86) ocfs2_bg_discontig_fix_result+0x1ef/0x230 (fs/ocfs2/suballoc.c:1786) ocfs2_search_chain+0x8f8/0x10a0 (fs/ocfs2/suballoc.c:1886) get_page_from_freelist+0x70e/0x2370 (?:?) lock_release+0xc6/0x290 (?:?) do_raw_spin_unlock+0x9a/0x100 (?:?) kasan_unpoison+0x27/0x60 (?:?) __bfs+0x147/0x240 (?:?) get_page_from_freelist+0x83d/0x2370 (?:?) ocfs2_claim_suballoc_bits+0x38c/0xe70 (fs/ocfs2/suballoc.c:96) sched_domains_numa_masks_clear+0x70/0xd0 (?:?) check_irq_usage+0xe8/0xb70 (?:?) __ocfs2_claim_clusters+0x18d/0x4c0 (fs/ocfs2/suballoc.c:2497) check_path+0x24/0x50 (?:?) rcu_is_watching+0x20/0x50 (?:?) check_prev_add+0xfd/0xd00 (?:?) ocfs2_add_clusters_in_btree+0x17d/0x810 (fs/ocfs2/suballoc.c:?) __folio_batch_add_and_move+0x1f5/0x3d0 (?:?) ocfs2_add_inode_data+0xd9/0x120 (fs/ocfs2/suballoc.c:?) filemap_add_folio+0x105/0x1f0 (?:?) ocfs2_write_begin_nolock+0x29f7/0x2f80 (fs/ocfs2/suballoc.c:3043) ocfs2_read_inode_block+0xb5/0x110 (fs/ocfs2/suballoc.c:?) down_write+0xf5/0x180 (?:?) ocfs2_write_begin+0x180/0x240 (fs/ocfs2/suballoc.c:?) __mark_inode_dirty+0x758/0x9a0 (?:?) inode_to_bdi+0x41/0x90 (?:?) balance_dirty_pages_ratelimited_flags+0xf8/0x1d0 (?:?) generic_perform_write+0x252/0x440 (?:?) mnt_put_write_access_file+0x16/0x70 (?:?) file_update_time_flags+0xe4/0x200 (?:?) ocfs2_file_write_iter+0x80a/0x1320 (fs/ocfs2/suballoc.c:?) lock_acquire+0x184/0x2f0 (?:?) ksys_write+0xd2/0x170 (?:?) apparmor_file_permission+0xf5/0x310 (?:?) read_zero+0x8d/0x140 (?:?) lock_is_held_type+0x8f/0x100 (?:?)

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
39%
KEV
Not listed

Published

July 19, 2026

Last Modified

August 17, 2026

Advisory Details (8)

Auto-updated Jul 20, 2026
No patch confirmed yet.
generic

ocfs2: reject oversized group bitmap descriptors - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/d2cd59fa848f9f13796ef214d3b1b5ca9a3fe21e
generic

ocfs2: reject oversized group bitmap descriptors - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/c5a125eadba05ba421c4b55e68da22b4a40d32b4
generic

ocfs2: reject oversized group bitmap descriptors - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/9bd541e09dffff27e5bec0f9f45b0228173a5375
generic

ocfs2: reject oversized group bitmap descriptors - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/99c21e7263248c3f084756bfae08163cc5d6c62f
generic

ocfs2: reject oversized group bitmap descriptors - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/8f9903b0cdbb3155a8899410330b4b4d583a7a5c
generic

ocfs2: reject oversized group bitmap descriptors - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/4cd57ebee395041099fcdfcabb00749ce38d8b27
generic

ocfs2: reject oversized group bitmap descriptors - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/336340a0f8a141df8a4eb21a5a86f8ffb87769f6
generic

ocfs2: reject oversized group bitmap descriptors - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/296c6a42b1174395935ca4cfe8f393e37b698d54

Vendor Advisories for CVE-2026-63796(2)

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

Affected Packages

(5 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 ... 6.1.176-1~deb11u1 (21 versions)6.1.177-1~deb11u1—
Debian:12(1)
PackageVulnerable rangeFixed inDependents
linux6.1.106-1 ... 6.1.99-1 (54 versions)6.1.177-1—
Debian:13(1)
PackageVulnerable rangeFixed inDependents
linux6.12.38-1 ... 6.12.95-1~bpo12+1 (29 versions)6.12.95-1—
Debian:14(1)
PackageVulnerable rangeFixed inDependents
linux6.12.100-1 ... 7.1~rc7-1~exp1 (153 versions)7.1.3-1—

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 34× in last 7d / 138× 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 180 total refreshes for this CVE.

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

Frequently asked(5)

What is CVE-2026-63796?
CVE-2026-63796 is a high vulnerability published on July 19, 2026. In the Linux kernel, the following vulnerability has been resolved: ocfs2: reject oversized group bitmap descriptors ocfs2validategdparent() only bounds bgbits against the parent allocator's chain geometry. A malicious descriptor can still claim a bgsize/bgbits pair that exceeds the bitmap bytes…
When was CVE-2026-63796 disclosed?
CVE-2026-63796 was first published in the National Vulnerability Database on July 19, 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-2026-63796 actively exploited?
CVE-2026-63796 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 60.5% of all scored CVEs.
What is the CVSS score of CVE-2026-63796?
CVE-2026-63796 has a CVSS v3 base score of 8.8 (NVD).
How do I remediate CVE-2026-63796?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-63796, 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

See which npm, PyPI, Go, and Maven packages are affected by CVE-2026-63796

Explore →

Is Your Infrastructure Affected by CVE-2026-63796?

EchelonGraph automatically scans your cloud infrastructure and maps CVE exposure using blast radius analysis.

Start Free Scan →Browse All CVEs