CVE-2026-90153

HIGHPre-NVD 8.18.1—
EchelonGraph scoreHIGH confidence

Score 8.1 from GitHub Security Advisory (severity: HIGH) published 2026-09-17. A secondary CVSS source baseline 8.1; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, secondary
Trending — 3 sources updated this week
8.1EG
EchelonGraph verdictPlan mitigationSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0.5%CVSS: 8.1Exploit: None knownExposed services: Not assessed

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

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

ksmbd: bound smb_check_perm_dacl() ACE walks by DACL size

smb_check_perm_dacl() validates that the DACL fits inside the NT security descriptor, but then bounds its two ACE walks by the remaining NTSD length (acl_size) rather than the DACL's declared size (pdacl_size).

When pdacl->size is smaller than the trailing NTSD buffer, bytes after the declared DACL boundary - still inside the stored security descriptor - are parsed as ACEs during access checks. A crafted DACL can place an access-granting ACE beyond pdacl->size, and the current code accepts it during SMB2_CREATE access validation, while parse_dacl() and smb_inherit_dacl() stop at pdacl_size.

Bound both ACE walks by pdacl_size to match the DACL boundary semantics used elsewhere in the server.

Validation:

  • semantic KUnit harness shows the post-boundary ACE is selected
before the fix and rejected (EACCES) after it
  • linux master (7.2-rc6), x86_64

CVSS v3
8.1
EG Score
8.1HIGHhigh confidence
EG Risk
41
EG Risk 41/100CISA SSVC

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
Severity81% × 45%
Exploitation0% × 40%
Automatability30% × 15%
CISA SSVC: Track at low or medium mission impact; Track or Attend at high (mission-essential systems).
Action: No fix is confirmed yet. Restrict network exposure of the affected system or apply the vendor's mitigation within your standard update timelines at low or medium mission impact and sooner than that at high, and watch the vendor's advisory for the fix.
EPSS PROB
0.5%
EPSS %ILE
39th
KEV
Not listed

CISA SSVCTrack at low or medium mission impact; Track or Attend at high (mission-essential systems).

No fix is confirmed yet. Restrict network exposure of the affected system or apply the vendor's mitigation within your standard update timelines at low or medium mission impact and sooner than that at high, and watch the vendor's advisory for the fix.

Exploitation none (no KEV listing, exploit record or EPSS ≥ 50%) · Automatable unknown (not published for this CVE) · Technical impact partial (CVSS below 9.0). Mission impact is CISA's Mission & Well-being decision point, and only you can judge it: high means the affected system is essential to your organisation's mission, or its compromise could cause irreversible harm to people. CISA's decision table

Published

September 17, 2026

Last Modified

September 18, 2026

Advisory Details (5)

Auto-updated Sep 18, 2026
No patch confirmed yet.
generic

ksmbd: bound smb_check_perm_dacl() ACE walks by DACL size - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/79decd88dd3f0d42e7fb0689b1a7853bfa302459
generic

ksmbd: bound smb_check_perm_dacl() ACE walks by DACL size - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/8e4f75e979c1d9a51b0a48ac33d0cfd5f039ec67
generic

ksmbd: bound smb_check_perm_dacl() ACE walks by DACL size - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/a4a307d149327dad5fb25187e1b03cebd1b04de6
generic

ksmbd: bound smb_check_perm_dacl() ACE walks by DACL size - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/a29f57a14c939586d84d7fd6a029bd1fd170098f
generic

ksmbd: bound smb_check_perm_dacl() ACE walks by DACL size - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/a2051ffe452afad52f580b85a3fd8851933b1e7c

Vendor Advisories for CVE-2026-90153(1)

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

Affected Packages

(4 across 3 ecosystems)
Debian:12(2)
PackageVulnerable rangeFix by version rangeDependents
linux6.1.106-1 ... 7.2~rc7-1~exp1 (360 versions)
  • every version on: no fix on record
—
linux-6.126.12.100-1~deb12u1, 6.12.101-1~deb12u1, 6.12.107-1~deb12u1
  • every version up to 6.12.111-1~deb12u1: fixed in 6.12.111-1~deb12u1
—
Debian:13(1)
PackageVulnerable rangeFix by version rangeDependents
linux6.12.100-1 ... 6.12.96-1 (35 versions)
  • every version up to 6.12.111-1: fixed in 6.12.111-1
—
Debian:14(1)
PackageVulnerable rangeFix by version rangeDependents
linux6.12.100-1 ... 7.2~rc7-1~exp1 (179 versions)
  • every version up to 7.2.6-1: fixed in 7.2.6-1
—

Data Freshness Timeline

(refreshed 28× in last 7d / 75× 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.

  1. 2026-10-05 06:29 UTCEG score recompute
  2. 2026-10-05 06:29 UTCGHSA enrichment
  3. 2026-10-04 23:22 UTCEPSS rescore
  4. 2026-10-04 19:28 UTCGHSA enrichment
  5. 2026-10-04 08:31 UTCGHSA enrichment
  6. 2026-10-03 21:35 UTCEG score recompute
  7. 2026-10-03 21:35 UTCGHSA enrichment
  8. 2026-10-03 10:39 UTCGHSA enrichment
  9. 2026-10-02 23:38 UTCEG score recompute
  10. 2026-10-02 23:38 UTCGHSA enrichment
  11. 2026-10-02 12:39 UTCGHSA enrichment
  12. 2026-10-02 01:44 UTCEG score recompute
  13. 2026-10-02 01:43 UTCGHSA enrichment
  14. 2026-10-01 19:51 UTCEPSS rescore
  15. 2026-10-01 14:45 UTCGHSA enrichment
  16. 2026-10-01 03:49 UTCGHSA enrichment
  17. 2026-09-30 16:53 UTCEG score recompute
  18. 2026-09-30 16:53 UTCGHSA enrichment
  19. 2026-09-30 15:04 UTCEPSS rescore
  20. 2026-09-30 05:20 UTCGHSA enrichment
  21. 2026-09-29 18:23 UTCEG score recompute
  22. 2026-09-29 18:23 UTCGHSA enrichment
  23. 2026-09-29 06:34 UTCEG score recompute
  24. 2026-09-29 06:34 UTCGHSA enrichment
  25. 2026-09-28 19:38 UTCEG score recompute
Show 50 more
  1. 2026-09-28 19:38 UTCGHSA enrichment
  2. 2026-09-28 13:52 UTCEPSS rescore
  3. 2026-09-28 13:52 UTCEPSS rescore
  4. 2026-09-28 08:38 UTCGHSA enrichment
  5. 2026-09-27 21:42 UTCEG score recompute
  6. 2026-09-27 21:42 UTCGHSA enrichment
  7. 2026-09-27 13:49 UTCEPSS rescore
  8. 2026-09-27 10:46 UTCGHSA enrichment
  9. 2026-09-26 23:45 UTCEG score recompute
  10. 2026-09-26 23:45 UTCGHSA enrichment
  11. 2026-09-26 15:59 UTCEPSS rescore
  12. 2026-09-26 12:48 UTCGHSA enrichment
  13. 2026-09-26 01:53 UTCEG score recompute
  14. 2026-09-26 01:52 UTCGHSA enrichment
  15. 2026-09-25 14:54 UTCGHSA enrichment
  16. 2026-09-25 03:59 UTCGHSA enrichment
  17. 2026-09-24 17:03 UTCEG score recompute
  18. 2026-09-24 17:03 UTCGHSA enrichment
  19. 2026-09-24 14:04 UTCEPSS rescore
  20. 2026-09-24 06:07 UTCGHSA enrichment
  21. 2026-09-23 19:11 UTCEG score recompute
  22. 2026-09-23 19:11 UTCGHSA enrichment
  23. 2026-09-23 17:54 UTCEPSS rescore
  24. 2026-09-23 07:55 UTCGHSA enrichment
  25. 2026-09-22 20:58 UTCEG score recompute
  26. 2026-09-22 20:58 UTCGHSA enrichment
  27. 2026-09-22 16:01 UTCEPSS rescore
  28. 2026-09-22 10:01 UTCGHSA enrichment
  29. 2026-09-21 23:05 UTCEG score recompute
  30. 2026-09-21 23:05 UTCGHSA enrichment
  31. 2026-09-21 21:09 UTCEPSS rescore
  32. 2026-09-21 12:09 UTCGHSA enrichment
  33. 2026-09-21 01:13 UTCEG score recompute
  34. 2026-09-21 01:13 UTCGHSA enrichment
  35. 2026-09-20 20:16 UTCEPSS rescore
  36. 2026-09-20 14:14 UTCGHSA enrichment
  37. 2026-09-20 03:18 UTCGHSA enrichment
  38. 2026-09-19 16:22 UTCEG score recompute
  39. 2026-09-19 16:22 UTCGHSA enrichment
  40. 2026-09-19 05:26 UTCEG score recompute
  41. 2026-09-19 05:26 UTCGHSA enrichment
  42. 2026-09-18 19:28 UTCEPSS rescore
  43. 2026-09-18 18:31 UTCEG score recompute
  44. 2026-09-18 18:31 UTCGHSA enrichment
  45. 2026-09-18 18:05 UTCEG score recompute▲ 8.10
  46. 2026-09-18 18:05 UTCGHSA enrichment
  47. 2026-09-18 17:59 UTCMITRE cvelistV5CVSS v3 → 8.1 · severity → HIGH
  48. 2026-09-17 17:23 UTCNVD update
  49. 2026-09-17 16:45 UTCEG score recompute
  50. 2026-09-17 16:19 UTCMITRE cvelistV5first tracked

Frequently asked(5)

What is CVE-2026-90153?
CVE-2026-90153 is a high vulnerability published on September 17, 2026. In the Linux kernel, the following vulnerability has been resolved: ksmbd: bound smbcheckperm_dacl() ACE walks by DACL size smbcheckperm_dacl() validates that the DACL fits inside the NT security descriptor, but then bounds its two ACE walks by the remaining NTSD length (acl_size) rather than the…
When was CVE-2026-90153 disclosed?
CVE-2026-90153 was first published on September 17, 2026, with the most recent update on September 18, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-90153 actively exploited?
CVE-2026-90153 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.5% probability of exploitation in the next 30 days (39th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-90153?
CVE-2026-90153 has a CVSS base score of 8.1 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
How do I remediate CVE-2026-90153?
No fix for CVE-2026-90153 is confirmed yet. Until one is published, restrict network exposure of the affected system or apply the vendor's mitigation — for example, keep it off the internet or limit it to trusted networks — and watch the vendor's advisory for the fix. The vendor advisories EchelonGraph has for CVE-2026-90153 are linked in the Vendor Advisories panel on this page.

Dependency Blast Radius

See which npm, PyPI, Go, and Maven packages are affected by CVE-2026-90153

Explore →

Is Your Infrastructure Affected by CVE-2026-90153?

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

Book a Demo →Browse All CVEs