CVE-2026-31446

HIGHPre-NVD 7.87.8—
EchelonGraph scoreMEDIUM confidence

Score 7.8 from GitHub Security Advisory (severity: HIGH) published 2026-04-22. the CNA's CVSS baseline 7.8; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: cna:linux, epss, ghsa
7.8EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 7.8Exploit: 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:

ext4: fix use-after-free in update_super_work when racing with umount

Commit b98535d09179 ("ext4: fix bug_on in start_this_handle during umount filesystem") moved ext4_unregister_sysfs() before flushing s_sb_upd_work to prevent new error work from being queued via /proc/fs/ext4/xx/mb_groups reads during unmount. However, this introduced a use-after-free because update_super_work calls ext4_notify_error_sysfs() -> sysfs_notify() which accesses the kobject's kernfs_node after it has been freed by kobject_del() in ext4_unregister_sysfs():

update_super_work ext4_put_super ----------------- -------------- ext4_unregister_sysfs(sb) kobject_del(&sbi->s_kobj) __kobject_del() sysfs_remove_dir() kobj->sd = NULL sysfs_put(sd) kernfs_put() // RCU free ext4_notify_error_sysfs(sbi) sysfs_notify(&sbi->s_kobj) kn = kobj->sd // stale pointer kernfs_get(kn) // UAF on freed kernfs_node ext4_journal_destroy() flush_work(&sbi->s_sb_upd_work)

Instead of reordering the teardown sequence, fix this by making ext4_notify_error_sysfs() detect that sysfs has already been torn down by checking s_kobj.state_in_sysfs, and skipping the sysfs_notify() call in that case. A dedicated mutex (s_error_notify_mutex) serializes ext4_notify_error_sysfs() against kobject_del() in ext4_unregister_sysfs() to prevent TOCTOU races where the kobject could be deleted between the state_in_sysfs check and the sysfs_notify() call.

CVSS v3
7.8
EG Score
7.8(medium)
EG Risk
40(Track)
EG Risk 40/100SSVC: 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
Severity78% × 45%
Exploitation0% × 40%
Automatability30% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
3%
KEV
Not listed

Published

April 22, 2026

Last Modified

August 5, 2026

Advisory Details (7)

Auto-updated May 7, 2026
No patch confirmed yet.
generic

ext4: fix use-after-free in update_super_work when racing with umount - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/d15e4b0a418537aafa56b2cb80d44add83e83697
generic

ext4: fix use-after-free in update_super_work when racing with umount - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/c97e282f7bfd0c3554c63d289964a5ca6a1d2ffe
generic

ext4: fix use-after-free in update_super_work when racing with umount - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/c8fe17a1b308c3d8c703ebfb049b325f844342c3
generic

ext4: fix use-after-free in update_super_work when racing with umount - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/c4d829737329f2290dd41e290b7d75effdb2a7ff
generic

ext4: fix use-after-free in update_super_work when racing with umount - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/9449f99ba04f5dd1c8423ad8a90b3651d7240d1d
generic

ext4: fix use-after-free in update_super_work when racing with umount - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/08b10e6f37fc533a759e9833af0692242e8b3f93
generic

ext4: fix use-after-free in update_super_work when racing with umount - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/034053378dd81837fd6c7a43b37ee2e58d4f0b4e

Vendor Advisories for CVE-2026-31446(2)

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

Patch Availability(1)

Vendor / EcosystemFixed in / PatchReleasedSource
linuxKernel @ 5.15.203—osv

Patches are aggregated from vendor advisories (Red Hat, Microsoft, Cisco, GitHub) and package ecosystems (OSV, GHSA). Multiple rows for the same upstream release have been deduplicated.

Affected Packages

(5 across 4 ecosystems)
Debian:11(2)
PackageVulnerable rangeFixed inDependents
linux5.10.103-1 ... 7.2~rc5-1~exp1 (496 versions)——
linux-6.16.1.106-3~deb11u1 ... 6.1.164-1~deb11u1 (16 versions)6.1.170-1~deb11u1—
Debian:12(1)
PackageVulnerable rangeFixed inDependents
linux6.1.106-1 ... 6.1.99-1 (48 versions)6.1.170-1—
Debian:13(1)
PackageVulnerable rangeFixed inDependents
linux6.12.38-1 ... 6.12.85-1~bpo12+1 (17 versions)6.12.85-1—
Debian:14(1)
PackageVulnerable rangeFixed inDependents
linux6.12.100-1 ... 6.19~rc8-1~exp1 (121 versions)6.19.11-1—

Weakness Classification(1)

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

Additional Vendor Advisories

(23)

Vendors that published advisories for this CVE beyond the curated set above. Broader coverage but minimal per-row detail — click through for the original advisory.

Data Freshness Timeline

(refreshed 8× in last 7d / 63× 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 239 total refreshes for this CVE.

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

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Frequently asked(5)

What is CVE-2026-31446?
CVE-2026-31446 is a high vulnerability published on April 22, 2026. In the Linux kernel, the following vulnerability has been resolved: ext4: fix use-after-free in updatesuperwork when racing with umount Commit b98535d09179 ("ext4: fix bugon in startthis_handle during umount filesystem") moved ext4unregistersysfs() before flushing ssbupd_work to prevent new error…
When was CVE-2026-31446 disclosed?
CVE-2026-31446 was first published in the National Vulnerability Database on April 22, 2026, with the most recent update on August 5, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-31446 actively exploited?
CVE-2026-31446 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 96.7% of all scored CVEs.
What is the CVSS score of CVE-2026-31446?
CVE-2026-31446 has a CVSS v4.0 base score of 7.8 (CNA self-assessment; NVD's own analysis pending).
How do I remediate CVE-2026-31446?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-31446, 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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