CVE-2026-43490

HIGHPre-NVD 8.88.8—
EchelonGraph scoreMEDIUM confidence

Score 8.8 from GitHub Security Advisory (severity: HIGH) published 2026-05-15. the CNA's CVSS baseline 8.8; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: cna:linux, epss, ghsa
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

A fix is available — apply it.

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

ksmbd: validate inherited ACE SID length

smb_inherit_dacl() walks the parent directory DACL loaded from the security descriptor xattr. It verifies that each ACE contains the fixed SID header before using it, but does not verify that the variable-length SID described by sid.num_subauth is fully contained in the ACE.

A malformed inheritable ACE can advertise more subauthorities than are present in the ACE. compare_sids() may then read past the ACE. smb_set_ace() also clamps the copied destination SID, but used the unchecked source SID count to compute the inherited ACE size. That could advance the temporary inherited ACE buffer pointer and nt_size accounting past the allocated buffer.

Fix this by validating the parent ACE SID count and SID length before using the SID during inheritance. Compute the inherited ACE size from the copied SID so the size matches the bounded destination SID. Reject the inherited DACL if size accumulation would overflow smb_acl.size or the security descriptor allocation size.

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
34%
KEV
Not listed

Published

May 15, 2026

Last Modified

August 5, 2026

Advisory Details (4)

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

ksmbd: validate inherited ACE SID length - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/c1d95c995d5bcb24b639200a899eda59cb1e6d64
generic

ksmbd: validate inherited ACE SID length - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/996454bc0da84d5a1dedb1a7861823087e01a7ae
generic

ksmbd: validate inherited ACE SID length - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/47c6e37a77b10e74f70d845ba4ea5d3cafa00336
generic

ksmbd: validate inherited ACE SID length - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/1aa60fea7f637c071f529ad6784aecca2f2f0c5f

Vendor Advisories for CVE-2026-43490(2)

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

Patch Availability(23)

Vendor / EcosystemFixed in / PatchReleasedSource
ubuntulinux-tools-raspi-realtime-6.8 (6.8.0-2050.52) @ noble2026-08-23ubuntu
ubuntulinux-virtual-hwe-26.04-edge (7.0.0-28.28) @ resolute2026-08-23ubuntu
ubuntulinux-virtual-6.8 (6.8.0-136.136) @ noble2026-08-23ubuntu
ubuntulinux-tools-oem-7.0 (7.0.0-1009.9) @ resolute2026-08-23ubuntu
ubuntulinux-virtual-hwe-24.04-edge (7.0.0-28.28~24.04.1) @ noble2026-08-23ubuntu
ubuntulinux-tools-gcp-fips-6.8 (6.8.0-1064.72+fips1) @ noble2026-08-23ubuntu
ubuntulinux-tools-oracle-7.0 (7.0.0-1008.8) @ resolute2026-08-23ubuntu
ubuntulinux-tools-oracle-lts-24.04 (6.8.0-1058.61) @ noble2026-08-23ubuntu
ubuntulinux-tools-oracle-edge (6.8.0-1058.61~22.04.1) @ jammy2026-08-23ubuntu
ubuntulinux-tools-nvidia-lowlatency-64k-6.8 (6.8.0-1059.62.1) @ noble2026-08-23ubuntu
ubuntulinux-tools-azure-fde-7.0 (7.0.0-1009.9) @ resolute2026-08-23ubuntu
ubuntulinux-tools-aws-lts-24.04 (6.8.0-1061.64+1) @ noble2026-08-23ubuntu
ubuntulinux-tools-azure-lts-24.04 (6.8.0-1063.71) @ noble2026-08-23ubuntu
ubuntulinux-tools-azure-fde-lts-24.04 (6.8.0-1062.69) @ noble2026-08-23ubuntu
ubuntulinux-tools-azure-fips-6.8 (6.8.0-1063.71+fips2) @ noble2026-08-23ubuntu
ubuntulinux-tools-azure-fde-6.8 (6.8.0-1062.69~22.04.1) @ jammy2026-08-23ubuntu
ubuntulinux-tools-raspi-realtime-7.0 (7.0.0-1015.15) @ resolute2026-08-23ubuntu
ubuntulinux-tools-aws-fips-6.8 (6.8.0-1061.64+fips1) @ noble2026-08-23ubuntu
ubuntulinux-xilinx-zynqmp (6.8.0.1033.34) @ noble2026-08-23ubuntu
ubuntulinux-virtual-hwe-22.04-edge (6.8.0-136.136~22.04.1) @ jammy2026-08-23ubuntu
ubuntulinux-tools-nvidia-hwe-24.04-edge (7.0.0-1016.16) @ resolute2026-08-23ubuntu
ubuntulinux-tools-nvidia-hwe-26.04 (7.0.0-2016.16) @ resolute2026-08-23ubuntu
linuxKernel @ 6.6.141—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

(3 across 3 ecosystems)
Debian:12(1)
PackageVulnerable rangeFixed inDependents
linux6.1.106-1 ... 7.2~rc5-1~exp1 (335 versions)——
Debian:13(1)
PackageVulnerable rangeFixed inDependents
linux6.12.38-1 ... 6.12.88-1~bpo12+1 (21 versions)6.12.88-1—
Debian:14(1)
PackageVulnerable rangeFixed inDependents
linux6.12.100-1 ... 7.0.7-1~bpo13+1 (133 versions)7.0.7-1—

Weakness Classification(1)

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

All Vendor Advisories

(22)

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 / 74× 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 222 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 17:32 UTCEG score recompute
  11. 2026-08-23 17:32 UTCVendor advisory
  12. 2026-08-23 17:31 UTCGHSA enrichment
  13. 2026-08-23 00:19 UTCEPSS rescore
  14. 2026-08-22 01:35 UTCEG score recompute
  15. 2026-08-22 01:35 UTCVendor advisory
  16. 2026-08-22 01:35 UTCGHSA enrichment
  17. 2026-08-21 23:49 UTCEPSS rescore
  18. 2026-08-20 22:55 UTCEPSS rescore
  19. 2026-08-20 19:27 UTCEG score recompute
  20. 2026-08-20 19:27 UTCVendor advisory
  21. 2026-08-20 19:27 UTCGHSA enrichment
  22. 2026-08-19 17:04 UTCEPSS rescore
  23. 2026-08-18 13:48 UTCEPSS rescore
  24. 2026-08-17 13:47 UTCEPSS rescore
  25. 2026-08-17 10:18 UTCEG score recompute
Show 75 more
  1. 2026-08-17 10:18 UTCVendor advisory
  2. 2026-08-17 10:18 UTCGHSA enrichment
  3. 2026-08-16 14:56 UTCEPSS rescore
  4. 2026-08-16 03:51 UTCEG score recompute
  5. 2026-08-16 03:51 UTCVendor advisory
  6. 2026-08-16 03:51 UTCGHSA enrichment
  7. 2026-08-16 02:14 UTCEPSS rescore
  8. 2026-08-15 01:30 UTCEPSS rescore
  9. 2026-08-14 15:05 UTCVendor advisory
  10. 2026-08-14 15:05 UTCGHSA enrichment
  11. 2026-08-14 02:20 UTCEG score recompute
  12. 2026-08-14 02:20 UTCVendor advisory
  13. 2026-08-14 02:20 UTCGHSA enrichment
  14. 2026-08-13 22:00 UTCEPSS rescore
  15. 2026-08-13 03:38 UTCVendor advisory
  16. 2026-08-13 03:38 UTCGHSA enrichment
  17. 2026-08-12 14:53 UTCEG score recompute
  18. 2026-08-12 14:53 UTCVendor advisory
  19. 2026-08-12 14:53 UTCGHSA enrichment
  20. 2026-08-12 13:51 UTCEPSS rescore
  21. 2026-08-11 14:01 UTCEG score recompute
  22. 2026-08-11 14:01 UTCVendor advisory
  23. 2026-08-11 14:01 UTCGHSA enrichment
  24. 2026-08-11 13:43 UTCEPSS rescore
  25. 2026-08-11 00:49 UTCEG score recompute
  26. 2026-08-11 00:49 UTCVendor advisory
  27. 2026-08-11 00:48 UTCGHSA enrichment
  28. 2026-08-11 00:00 UTCEPSS rescore
  29. 2026-08-10 03:15 UTCVendor advisory
  30. 2026-08-10 03:15 UTCGHSA enrichment
  31. 2026-08-09 14:31 UTCEG score recompute
  32. 2026-08-09 14:31 UTCVendor advisory
  33. 2026-08-09 14:31 UTCGHSA enrichment
  34. 2026-08-09 13:46 UTCEPSS rescore
  35. 2026-08-09 01:46 UTCEG score recompute
  36. 2026-08-09 01:46 UTCVendor advisory
  37. 2026-08-09 01:46 UTCGHSA enrichment
  38. 2026-08-08 16:37 UTCEPSS rescore
  39. 2026-08-08 05:36 UTCVendor advisory
  40. 2026-08-08 05:36 UTCGHSA enrichment
  41. 2026-08-07 16:51 UTCEG score recompute
  42. 2026-08-07 16:51 UTCVendor advisory
  43. 2026-08-07 16:51 UTCGHSA enrichment
  44. 2026-08-07 04:06 UTCVendor advisory
  45. 2026-08-07 04:06 UTCGHSA enrichment
  46. 2026-08-06 15:20 UTCEG score recompute
  47. 2026-08-06 15:20 UTCVendor advisory
  48. 2026-08-06 15:20 UTCGHSA enrichment
  49. 2026-08-06 13:46 UTCEPSS rescore
  50. 2026-08-06 02:29 UTCEG score recompute
  51. 2026-08-06 02:29 UTCVendor advisory
  52. 2026-08-06 02:29 UTCGHSA enrichment
  53. 2026-08-05 19:17 UTCEPSS rescore
  54. 2026-08-05 13:44 UTCEG score recompute
  55. 2026-08-05 13:44 UTCVendor advisory
  56. 2026-08-05 13:44 UTCGHSA enrichment
  57. 2026-08-04 15:10 UTCEPSS rescore
  58. 2026-08-04 10:38 UTCEPSS rescore
  59. 2026-08-03 18:56 UTCEG score recompute
  60. 2026-08-03 18:56 UTCVendor advisory
  61. 2026-08-03 18:56 UTCGHSA enrichment
  62. 2026-08-03 10:36 UTCEPSS rescore
  63. 2026-08-02 20:39 UTCVendor advisory
  64. 2026-08-02 20:39 UTCGHSA enrichment
  65. 2026-08-02 07:54 UTCEG score recompute
  66. 2026-08-02 07:54 UTCVendor advisory
  67. 2026-08-02 07:54 UTCGHSA enrichment
  68. 2026-08-02 02:27 UTCEPSS rescore
  69. 2026-08-01 19:02 UTCEG score recompute
  70. 2026-08-01 19:02 UTCVendor advisory
  71. 2026-08-01 19:02 UTCGHSA enrichment
  72. 2026-08-01 04:16 UTCEPSS rescore
  73. 2026-07-30 16:28 UTCEPSS rescore
  74. 2026-07-30 01:30 UTCEPSS rescore
  75. 2026-07-28 15:36 UTCEPSS rescore

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

Frequently asked(5)

What is CVE-2026-43490?
CVE-2026-43490 is a high vulnerability published on May 15, 2026. In the Linux kernel, the following vulnerability has been resolved: ksmbd: validate inherited ACE SID length smbinheritdacl() walks the parent directory DACL loaded from the security descriptor xattr. It verifies that each ACE contains the fixed SID header before using it, but does not verify that…
When was CVE-2026-43490 disclosed?
CVE-2026-43490 was first published in the National Vulnerability Database on May 15, 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-2026-43490 actively exploited?
CVE-2026-43490 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 66.0% of all scored CVEs.
What is the CVSS score of CVE-2026-43490?
CVE-2026-43490 has a CVSS v4.0 base score of 8.8 (CNA self-assessment; NVD's own analysis pending).
How do I remediate CVE-2026-43490?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-43490, 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-2026-43490

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