CVE-2026-43376

CRITICALNVD 9.89.8—
EchelonGraph scoreMEDIUM confidence

Score 9.8 from GitHub Security Advisory (severity: CRITICAL) published 2026-05-08. NVD baseline CVSS 9.8; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, nvd
9.8EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 9.8Exploit: None knownExposed: 0

A fix is available — apply it.

In the Linux kernel, the following vulnerability has been resolved:

ksmbd: fix use-after-free by using call_rcu() for oplock_info

ksmbd currently frees oplock_info immediately using kfree(), even though it is accessed under RCU read-side critical sections in places like opinfo_get() and proc_show_files().

Since there is no RCU grace period delay between nullifying the pointer and freeing the memory, a reader can still access oplock_info structure after it has been freed. This can leads to a use-after-free especially in opinfo_get() where atomic_inc_not_zero() is called on already freed memory.

Fix this by switching to deferred freeing using call_rcu().

CVSS v3
9.8
EG Score
9.8(medium)
EG Risk
49(Track)
EG Risk 49/100SSVC: 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
Severity98% × 45%
Exploitation0% × 40%
Automatability30% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
37%
KEV
Not listed

Published

May 8, 2026

Last Modified

August 5, 2026

Advisory Details (5)

Auto-updated Sep 2, 2026
No patch confirmed yet.
generic

ksmbd: fix use-after-free by using call_rcu() for oplock_info - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/1dfd062caa165ec9d7ee0823087930f3ab8a6294
generic

ksmbd: fix use-after-free by using call_rcu() for oplock_info - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/ce8507ee82c888126d8e7565e27c016308d24cde
generic

ksmbd: fix use-after-free by using call_rcu() for oplock_info - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/1d6abf145615dbfe267ce3b0a271f95e3780e18e
generic

ksmbd: fix use-after-free by using call_rcu() for oplock_info - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/08aa9f3c8cf4d0bee44df540dfe34e8d64069f2c
generic

ksmbd: fix use-after-free by using call_rcu() for oplock_info - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/302fef75512b2c8329a3f5efab1ae7ba2562387a

Vendor Advisories for CVE-2026-43376(1)

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

Patch Availability(9)

Vendor / EcosystemFixed in / PatchReleasedSource
ubuntulinux-virtual-hwe-24.04-edge (6.17.0-40.40) @ questing2026-08-23ubuntu
ubuntulinux-tools-oem-6.17 (6.17.0-1028.28) @ noble2026-08-23ubuntu
ubuntulinux-tools-nvidia-hwe-24.04 (6.17.0-1026.26) @ noble2026-08-23ubuntu
ubuntulinux-tools-realtime-hwe-24.04-edge (6.17.0-1017.19) @ questing2026-08-23ubuntu
ubuntulinux-virtual-hwe-24.04 (6.17.0-40.40~24.04.1) @ noble2026-08-23ubuntu
ubuntulinux-tools-azure-fde-6.17 (6.17.0-1018.18~24.04.1) @ noble2026-08-23ubuntu
ubuntulinux-tools-raspi-6.17 (6.17.0-1021.21) @ questing2026-08-23ubuntu
ubuntulinux-tools-azure-6.17 (6.17.0-1021.21~24.04.1) @ noble2026-08-23ubuntu
linuxKernel @ 6.6.130—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

(2 across 2 ecosystems)
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 (119 versions)6.19.10-1—

Weakness Classification(1)

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

All Vendor Advisories

(8)

Every vendor that published an advisory referencing this CVE — pulled from our cve_vendor_advisories aggregation. Click any row for the vendor's original advisory page.

Data Freshness Timeline

(refreshed 5× in last 7d / 127× 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 349 total refreshes for this CVE.

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

Related CVEs(same product + same vendor + same CWE)

Frequently asked(5)

What is CVE-2026-43376?
CVE-2026-43376 is a critical vulnerability published on May 8, 2026. In the Linux kernel, the following vulnerability has been resolved: ksmbd: fix use-after-free by using callrcu() for oplockinfo ksmbd currently frees oplock_info immediately using kfree(), even though it is accessed under RCU read-side critical sections in places like opinfoget() and…
When was CVE-2026-43376 disclosed?
CVE-2026-43376 was first published in the National Vulnerability Database on May 8, 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-2026-43376 actively exploited?
CVE-2026-43376 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 62.8% of all scored CVEs.
What is the CVSS score of CVE-2026-43376?
CVE-2026-43376 has a CVSS v3 base score of 9.8 (NVD).
How do I remediate CVE-2026-43376?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-43376, 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-2026-43376

Explore →

Is Your Infrastructure Affected by CVE-2026-43376?

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

Start Free Scan →Browse All CVEs