CVE-2026-40393

CRITICALNVD 9.89.8—
EchelonGraph scoreMEDIUM confidence

This critical-severity CVE scores 9.8 under NVD CVSS v3. EPSS exploit probability: 0.4%, top 64% of all CVEs by exploit prediction. GitHub Security Advisory enrichment pending alignment with NVD CVSS.

Triggered by: NVD CVSS baseline
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

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

In Mesa before 25.3.6 and 26 before 26.0.1, out-of-bounds memory access can occur in WebGPU because the amount of to-be-allocated data depends on an untrusted party, and is then used for alloca.

CVSS v3
9.8
EG Score
9.8(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
Severity98% × 45%
Exploitation0% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
36%
KEV
Not listed

Published

April 12, 2026

Last Modified

July 13, 2026

Advisory Details (3)

Auto-updated Aug 29, 2026
Patch available.
generic Patch Available

[SECURITY] [DLA 4679-1] mesa security update

https://lists.debian.org/debian-lts-announce/2026/07/msg00021.html
generic

[ANNOUNCE] mesa 26.0.1

https://lists.freedesktop.org/archives/mesa-dev/2026-February/226597.html
generic

spirv: nir: Use STACK_ARRAY instead of NIR_VLA (!39866) · Merge requests · Mesa / mesa · GitLab

https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/39866

Vendor Advisories for CVE-2026-40393(2)

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 4 ecosystems)
Debian:11(1)
PackageVulnerable rangeFixed inDependents
mesa20.3.5-120.3.5-1+deb11u1—
Debian:12(1)
PackageVulnerable rangeFixed inDependents
mesa22.3.6-1+deb12u122.3.6-1+deb12u2—
Debian:13(1)
PackageVulnerable rangeFixed inDependents
mesa25.0.7-225.0.7-2+deb13u1—
Debian:14(1)
PackageVulnerable rangeFixed inDependents
mesa25.0.7-2 ... 26.0.0~rc3-1 (29 versions)26.0.1-1—

Weakness Classification(1)

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

Additional Vendor Advisories

(1)

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 6× in last 7d / 104× 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 253 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 13:53 UTCEPSS rescore
  4. 2026-09-01 04:39 UTCEPSS rescore
  5. 2026-08-30 19:17 UTCEPSS rescore
  6. 2026-08-30 01:22 UTCEPSS rescore
  7. 2026-08-28 21:41 UTCEPSS rescore
  8. 2026-08-27 14:25 UTCEPSS rescore
  9. 2026-08-26 14:46 UTCEPSS rescore
  10. 2026-08-25 13:49 UTCEPSS rescore
  11. 2026-08-23 00:19 UTCEPSS rescore
  12. 2026-08-21 23:49 UTCEPSS rescore
  13. 2026-08-20 22:55 UTCEPSS rescore
  14. 2026-08-19 17:03 UTCEPSS rescore
  15. 2026-08-18 13:48 UTCEPSS rescore
  16. 2026-08-17 13:47 UTCEPSS rescore
  17. 2026-08-16 14:56 UTCEPSS rescore
  18. 2026-08-16 10:52 UTCVendor advisory
  19. 2026-08-16 10:52 UTCGHSA enrichment
  20. 2026-08-16 06:58 UTCEG score recompute
  21. 2026-08-16 06:58 UTCVendor advisory
  22. 2026-08-16 06:58 UTCGHSA enrichment
  23. 2026-08-16 02:14 UTCEPSS rescore
  24. 2026-08-15 02:15 UTCEG score recompute
  25. 2026-08-15 02:15 UTCVendor advisory
Show 75 more
  1. 2026-08-15 02:15 UTCGHSA enrichment
  2. 2026-08-15 01:30 UTCEPSS rescore
  3. 2026-08-14 22:21 UTCVendor advisory
  4. 2026-08-14 22:21 UTCGHSA enrichment
  5. 2026-08-14 18:18 UTCVendor advisory
  6. 2026-08-14 18:18 UTCGHSA enrichment
  7. 2026-08-14 12:48 UTCVendor advisory
  8. 2026-08-14 12:48 UTCGHSA enrichment
  9. 2026-08-14 08:54 UTCVendor advisory
  10. 2026-08-14 08:54 UTCGHSA enrichment
  11. 2026-08-14 04:59 UTCEG score recompute
  12. 2026-08-14 04:59 UTCVendor advisory
  13. 2026-08-14 04:59 UTCGHSA enrichment
  14. 2026-08-13 22:00 UTCEPSS rescore
  15. 2026-08-13 09:17 UTCVendor advisory
  16. 2026-08-13 09:17 UTCGHSA enrichment
  17. 2026-08-13 03:00 UTCVendor advisory
  18. 2026-08-13 03:00 UTCGHSA enrichment
  19. 2026-08-12 23:06 UTCVendor advisory
  20. 2026-08-12 23:06 UTCGHSA enrichment
  21. 2026-08-12 19:12 UTCEG score recompute
  22. 2026-08-12 19:12 UTCVendor advisory
  23. 2026-08-12 19:12 UTCGHSA enrichment
  24. 2026-08-12 13:51 UTCEPSS rescore
  25. 2026-08-11 23:15 UTCVendor advisory
  26. 2026-08-11 23:15 UTCGHSA enrichment
  27. 2026-08-11 19:21 UTCEG score recompute
  28. 2026-08-11 19:21 UTCVendor advisory
  29. 2026-08-11 19:21 UTCGHSA enrichment
  30. 2026-08-11 13:43 UTCEPSS rescore
  31. 2026-08-11 06:47 UTCVendor advisory
  32. 2026-08-11 06:47 UTCGHSA enrichment
  33. 2026-08-11 02:53 UTCEG score recompute
  34. 2026-08-11 02:53 UTCVendor advisory
  35. 2026-08-11 02:53 UTCGHSA enrichment
  36. 2026-08-11 00:00 UTCEPSS rescore
  37. 2026-08-10 12:13 UTCVendor advisory
  38. 2026-08-10 12:13 UTCGHSA enrichment
  39. 2026-08-10 08:19 UTCVendor advisory
  40. 2026-08-10 08:19 UTCGHSA enrichment
  41. 2026-08-10 04:25 UTCVendor advisory
  42. 2026-08-10 04:25 UTCGHSA enrichment
  43. 2026-08-10 00:31 UTCVendor advisory
  44. 2026-08-10 00:31 UTCGHSA enrichment
  45. 2026-08-09 20:37 UTCVendor advisory
  46. 2026-08-09 20:37 UTCGHSA enrichment
  47. 2026-08-09 16:43 UTCEG score recompute
  48. 2026-08-09 16:43 UTCVendor advisory
  49. 2026-08-09 16:43 UTCGHSA enrichment
  50. 2026-08-09 13:46 UTCEPSS rescore
  51. 2026-08-09 12:48 UTCVendor advisory
  52. 2026-08-09 12:48 UTCGHSA enrichment
  53. 2026-08-09 08:17 UTCVendor advisory
  54. 2026-08-09 08:17 UTCGHSA enrichment
  55. 2026-08-09 04:23 UTCEG score recompute
  56. 2026-08-09 04:23 UTCVendor advisory
  57. 2026-08-09 04:23 UTCGHSA enrichment
  58. 2026-08-08 16:37 UTCEPSS rescore
  59. 2026-08-08 09:39 UTCVendor advisory
  60. 2026-08-08 09:39 UTCGHSA enrichment
  61. 2026-08-08 05:45 UTCVendor advisory
  62. 2026-08-08 05:45 UTCGHSA enrichment
  63. 2026-08-08 01:51 UTCVendor advisory
  64. 2026-08-08 01:51 UTCGHSA enrichment
  65. 2026-08-07 21:57 UTCVendor advisory
  66. 2026-08-07 21:57 UTCGHSA enrichment
  67. 2026-08-07 18:03 UTCEG score recompute
  68. 2026-08-07 18:03 UTCVendor advisory
  69. 2026-08-07 18:03 UTCGHSA enrichment
  70. 2026-08-07 14:09 UTCVendor advisory
  71. 2026-08-07 14:09 UTCGHSA enrichment
  72. 2026-08-06 17:30 UTCEG score recompute
  73. 2026-08-06 17:30 UTCVendor advisory
  74. 2026-08-06 17:30 UTCGHSA enrichment
  75. 2026-08-06 13:46 UTCEPSS rescore

Frequently asked(5)

What is CVE-2026-40393?
CVE-2026-40393 is a critical vulnerability published on April 12, 2026. In Mesa before 25.3.6 and 26 before 26.0.1, out-of-bounds memory access can occur in WebGPU because the amount of to-be-allocated data depends on an untrusted party, and is then used for alloca.
When was CVE-2026-40393 disclosed?
CVE-2026-40393 was first published in the National Vulnerability Database on April 12, 2026, with the most recent update on July 13, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-40393 actively exploited?
CVE-2026-40393 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 64.2% of all scored CVEs.
What is the CVSS score of CVE-2026-40393?
CVE-2026-40393 has a CVSS v3 base score of 9.8 (NVD).
How do I remediate CVE-2026-40393?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-40393, 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.

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