CVE-2026-40393

CRITICALNVD 9.89.8
EchelonGraph scoreMEDIUM confidence

“—” beside the score: it is equal to NVD's CVSS score.

This critical-severity CVE scores 9.8 under NVD CVSS v3. EPSS exploit probability: 0.4% (36th percentile of EPSS-scored CVEs). GitHub Security Advisory CVSS 8.1 is lower than this score; a lower GitHub score revises it only when its advisory is newer than the CVE record's last change, and this advisory (published 2026-04-12) is not newer than that change (2026-10-26), so it does not.

Triggered by: Headline CVSS from NVD CVSS v3
Sources: EPSS, GitHub Security Advisory, NVD CVSS v3
Trending — 4 sources updated this week

Also known asEUVD-2026-21737 (ENISA EUVD) · GHSA-w54f-pw7x-c532 (GitHub Security Advisories)Source: ENISA EUVD

9.8EG
EchelonGraph verdictPlan a fixRemediate within your standard update timelines (the SSVC decision on this page).
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0.4%CVSS: 9.8Exploit: None knownExposed services: Not assessed

A fix is available — apply it.

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
9.8CRITICALmedium confidence
EG Risk
44
EG Risk 44/100

EG Risk is EchelonGraph's 0–100 priority score. It fuses impact severity (EG Severity, the CVSS base score, never the KEV-floored or EPSS-lifted EG Score) with real-world exploitation and automatability, under weights EchelonGraph set by hand, so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner.

How it’s computed (value × EchelonGraph’s weight)
Severity98% × 45%
Impact severity (EG Severity): CVSS 9.8 of 10. Never the KEV-floored or EPSS-lifted EG Score.
Exploitation0.4% × 40%
FIRST EPSS: the 30-day exploitation probability when EchelonGraph scored this CVE.
Automatability0% × 15%
CISA's SSVC Automatable value: no (Vulnrichment).
SSVC (CISA's decision table, applied by EchelonGraph): Track at low or medium mission impact; Track* at high (mission-essential systems).
Exploitation none (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact total (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE.
Action: A fix is available. Apply it within your standard update timelines.
EPSS PROB
0.4%
EPSS %ILE
36th
KEV
Not listed

What the EG score is made of (scorer v4.0: the three questions the 0–10 score mixes, published apart · methodology)

The EG score (9.8): severity, escalated by confirmed exploitation. This CVE's 9.8 is its impact severity (EG Severity), not escalated.

EG Severity
9.8 CRITICALCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.NVD CVSS v3 · CVSS v3.0 or v3.1
EG Likelihood
0.4% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-10-29). FIRST's exploitation probability, not an EchelonGraph model.
Confirmed exploitation
None on record (CISA KEV, EG-KEV Tier 1)Reported apart from the likelihood: an observed fact, not a probability.
EG Priority
SSVC Track at medium mission impactTrack at low or medium mission impact; Track* at high (mission-essential systems).CISA BOD 26-04: 14 days if the affected system is publicly exposed; Fix on system upgrade if it is not.Each input and its source: the SSVC and BOD 26-04 blocks below.

SSVC (CISA's decision table, applied by EchelonGraph)Track at low or medium mission impact; Track* at high (mission-essential systems).

A fix is available. Apply it within your standard update timelines.

Exploitation none (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact total (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE. Mission impact is CISA's Mission & Well-being decision point, and only you can judge it. CISA's table makes it high when Mission Prevalence is Essential — the vulnerable component "directly provides capabilities that constitute at least one MEF for at least one entity" (MEF: mission essential function) — or when Public Well-Being Impact is Irreversible: "multiple fatalities are likely", the cyber-physical system "is likely lost or destroyed", "extreme or serious externalities" are imposed on other parties, or social systems such as elections or the financial grid "are destabilized and potentially collapse". CISA's decision table

BOD 26-04 (CISA's remediation timeline, Table 1)14 days if the affected system is publicly exposed; Fix on system upgrade if it is not.

In CISA KEV no (CISA's KEV catalog) · Automatable no (CISA Vulnrichment) · Technical impact total (CISA Vulnrichment). Whether your system is publicly exposed is yours to answer. BOD 26-04 binds US Federal Civilian Executive Branch agencies; for anyone else it is CISA's published timeline, a reference rather than an obligation. The directive · how EchelonGraph applies it

Published

April 12, 2026

Last Modified

October 26, 2026

Advisory Details (3)

Auto-updated Oct 27, 2026
Patch available.
Web pageMentions a patch (unverified)

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

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

[ANNOUNCE] mesa 26.0.1

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

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.

Patch Availability(1)

Vendor / EcosystemFix (by version range) / PatchReleasedSource
ubuntumesa-vulkan-drivers (25.2.8-0ubuntu0.25.10.2) @ questing2026-10-30ubuntu

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

(4 across 4 ecosystems)
Debian:11(1)
PackageVulnerable rangeFix by version rangeDependents
mesa20.3.5-1
  • every version up to 20.3.5-1+deb11u1: fixed in 20.3.5-1+deb11u1
—
Debian:12(1)
PackageVulnerable rangeFix by version rangeDependents
mesa22.3.6-1+deb12u1
  • every version up to 22.3.6-1+deb12u2: fixed in 22.3.6-1+deb12u2
—
Debian:13(1)
PackageVulnerable rangeFix by version rangeDependents
mesa25.0.7-2
  • every version up to 25.0.7-2+deb13u1: fixed in 25.0.7-2+deb13u1
—
Debian:14(1)
PackageVulnerable rangeFix by version rangeDependents
mesa25.0.7-2 ... 26.0.0~rc3-1 (29 versions)
  • every version up to 26.0.1-1: fixed in 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 27× in last 7d / 81× in last 30d)

Each row is a time one of our pipelines fetched, updated or re-scored this CVE. 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. An arrow marks a change the record states ("CVSS v3 → 9.1"); EPSS and GHSA rows show the values recorded at that time, not what changed (EPSS values are rounded; hover one for the exact figures). Most recent first.

Showing the most recent 99 of 351 refreshes on record for this CVE.

A repeat, a row identical to one the same pipeline wrote less than 10 seconds earlier, is not a separate refresh and is not counted. 1 repeat row among the latest 100 is merged into the row it repeats. The 252 oldest rows on record are not shown and were not checked, so the counts can still include repeats.

  1. 2026-10-30 04:12 UTCEG score recompute
  2. 2026-10-30 04:12 UTCVendor advisory
  3. 2026-10-30 04:12 UTCGHSA enrichmentGHSA-w54f-pw7x-c532 · GitHub severity HIGH · GitHub CVSS 8.1
  4. 2026-10-29 16:33 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  5. 2026-10-29 01:58 UTCEG score recompute
  6. 2026-10-29 01:58 UTCVendor advisory
  7. 2026-10-29 01:58 UTCGHSA enrichmentGHSA-w54f-pw7x-c532 · GitHub severity HIGH · GitHub CVSS 8.1
  8. 2026-10-28 16:32 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  9. 2026-10-27 23:45 UTCEG score recompute
  10. 2026-10-27 23:44 UTCGHSA enrichmentGHSA-w54f-pw7x-c532 · GitHub severity HIGH · GitHub CVSS 8.1
  11. 2026-10-27 16:31 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  12. 2026-10-26 21:29 UTCEG score recompute
  13. 2026-10-26 21:29 UTCVendor advisory
  14. 2026-10-26 21:29 UTCGHSA enrichmentGHSA-w54f-pw7x-c532 · GitHub severity HIGH · GitHub CVSS 8.1
  15. 2026-10-26 20:17 UTCEG score recompute
  16. 2026-10-26 20:17 UTCVendor advisory
  17. 2026-10-26 20:17 UTCGHSA enrichmentGHSA-w54f-pw7x-c532 · GitHub severity HIGH · GitHub CVSS 8.1
  18. 2026-10-26 16:31 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  19. 2026-10-25 16:32 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  20. 2026-10-25 16:11 UTCVendor advisory
  21. 2026-10-25 16:11 UTCGHSA enrichmentGHSA-w54f-pw7x-c532 · GitHub severity HIGH · GitHub CVSS 8.1
  22. 2026-10-25 14:31 UTCEG score recompute
  23. 2026-10-24 16:32 UTCEPSS rescoreEPSS 0.6% · 48th percentile
  24. 2026-10-24 13:56 UTCEG score recompute
  25. 2026-10-24 13:56 UTCVendor advisory
Show 74 more
  1. 2026-10-24 13:56 UTCGHSA enrichmentGHSA-w54f-pw7x-c532 · GitHub severity HIGH · GitHub CVSS 8.1
  2. 2026-10-23 16:31 UTCEPSS rescoreEPSS 0.6% · 48th percentile
  3. 2026-10-23 11:43 UTCEG score recompute
  4. 2026-10-23 11:42 UTCGHSA enrichmentGHSA-w54f-pw7x-c532 · GitHub severity HIGH · GitHub CVSS 8.1
  5. 2026-10-22 16:34 UTCEPSS rescoreEPSS 0.6% · 48th percentile
  6. 2026-10-22 09:27 UTCEG score recompute
  7. 2026-10-22 09:27 UTCVendor advisory
  8. 2026-10-22 09:27 UTCGHSA enrichmentGHSA-w54f-pw7x-c532 · GitHub severity HIGH · GitHub CVSS 8.1
  9. 2026-10-21 16:33 UTCEPSS rescoreEPSS 0.6% · 48th percentile
  10. 2026-10-21 07:14 UTCEG score recompute
  11. 2026-10-21 07:14 UTCVendor advisory
  12. 2026-10-21 07:14 UTCGHSA enrichmentGHSA-w54f-pw7x-c532 · GitHub severity HIGH · GitHub CVSS 8.1
  13. 2026-10-20 16:33 UTCEPSS rescoreEPSS 0.6% · 48th percentile
  14. 2026-10-20 04:59 UTCEG score recompute
  15. 2026-10-20 04:59 UTCVendor advisory
  16. 2026-10-20 04:59 UTCGHSA enrichmentGHSA-w54f-pw7x-c532 · GitHub severity HIGH · GitHub CVSS 8.1
  17. 2026-10-19 16:32 UTCEPSS rescoreEPSS 0.6% · 48th percentile
  18. 2026-10-19 02:44 UTCEG score recompute
  19. 2026-10-19 02:44 UTCVendor advisory
  20. 2026-10-19 02:43 UTCGHSA enrichmentGHSA-w54f-pw7x-c532 · GitHub severity HIGH · GitHub CVSS 8.1
  21. 2026-10-18 16:32 UTCEPSS rescoreEPSS 0.6% · 48th percentile
  22. 2026-10-18 03:42 UTCEG score recompute
  23. 2026-10-18 00:29 UTCEG score recompute
  24. 2026-10-18 00:29 UTCVendor advisory
  25. 2026-10-18 00:29 UTCGHSA enrichmentGHSA-w54f-pw7x-c532 · GitHub severity HIGH · GitHub CVSS 8.1
  26. 2026-10-17 16:34 UTCEPSS rescoreEPSS 0.6% · 48th percentile
  27. 2026-10-16 22:16 UTCEG score recompute
  28. 2026-10-16 22:15 UTCGHSA enrichmentGHSA-w54f-pw7x-c532 · GitHub severity HIGH · GitHub CVSS 8.1
  29. 2026-10-16 16:42 UTCEPSS rescoreEPSS 0.6% · 48th percentile
  30. 2026-10-15 18:53 UTCEG score recompute
  31. 2026-10-15 18:53 UTCGHSA enrichmentGHSA-w54f-pw7x-c532 · GitHub severity HIGH · GitHub CVSS 8.1
  32. 2026-10-15 16:32 UTCEPSS rescoreEPSS 0.6% · 48th percentile
  33. 2026-10-14 16:33 UTCEPSS rescoreEPSS 0.6% · 48th percentile
  34. 2026-10-14 12:36 UTCEG score recompute
  35. 2026-10-14 12:36 UTCGHSA enrichmentGHSA-w54f-pw7x-c532 · GitHub severity HIGH · GitHub CVSS 8.1
  36. 2026-10-13 16:34 UTCEPSS rescoreEPSS 0.6% · 48th percentile
  37. 2026-10-13 10:21 UTCEG score recompute
  38. 2026-10-13 10:21 UTCVendor advisory
  39. 2026-10-13 10:20 UTCGHSA enrichmentGHSA-w54f-pw7x-c532 · GitHub severity HIGH · GitHub CVSS 8.1
  40. 2026-10-12 16:34 UTCEPSS rescoreEPSS 0.6% · 47th percentile
  41. 2026-10-12 16:09 UTCEG score recompute
  42. 2026-10-12 08:06 UTCVendor advisory
  43. 2026-10-12 08:06 UTCGHSA enrichmentGHSA-w54f-pw7x-c532 · GitHub severity HIGH · GitHub CVSS 8.1
  44. 2026-10-11 19:51 UTCEG score recompute
  45. 2026-10-11 17:05 UTCEG score recompute
  46. 2026-10-11 14:31 UTCEG score recompute
  47. 2026-10-11 13:48 UTCEPSS rescoreEPSS 0.6% · 47th percentile
  48. 2026-10-10 20:00 UTCEPSS rescoreEPSS 0.6% · 47th percentile
  49. 2026-10-09 20:07 UTCEPSS rescoreEPSS 0.6% · 47th percentile
  50. 2026-10-08 17:12 UTCEPSS rescoreEPSS 0.6% · 47th percentile
  51. 2026-10-07 23:48 UTCEPSS rescoreEPSS 0.6% · 47th percentile
  52. 2026-10-06 15:17 UTCEPSS rescoreEPSS 0.6% · 47th percentile
  53. 2026-10-05 17:43 UTCEPSS rescoreEPSS 0.6% · 47th percentile
  54. 2026-10-04 23:22 UTCEPSS rescoreEPSS 0.6% · 47th percentile
  55. 2026-10-03 14:25 UTCEPSS rescoreEPSS 0.6% · 47th percentile
  56. 2026-10-01 19:50 UTCEPSS rescoreEPSS 0.6% · 47th percentile
  57. 2026-09-30 15:03 UTCEPSS rescoreEPSS 0.6% · 47th percentile
  58. 2026-09-27 13:48 UTCEPSS rescoreEPSS 0.6% · 47th percentile
  59. 2026-09-26 15:58 UTCEPSS rescoreEPSS 0.6% · 47th percentile
  60. 2026-09-20 20:15 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  61. 2026-09-18 19:28 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  62. 2026-09-17 19:30 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  63. 2026-09-16 14:08 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  64. 2026-09-16 05:15 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  65. 2026-09-15 03:11 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  66. 2026-09-13 16:47 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  67. 2026-09-12 15:01 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  68. 2026-09-11 14:53 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  69. 2026-09-11 09:37 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  70. 2026-09-10 09:34 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  71. 2026-09-08 22:00 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  72. 2026-09-07 16:01 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  73. 2026-09-06 13:47 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  74. 2026-09-04 05:06 UTCEPSS rescoreEPSS 0.4% · 35th percentile

Related CVEs(same product + same CWE)

Frequently asked(5)

What is CVE-2026-40393?
CVE-2026-40393 is a critical-severity vulnerability; its CVE record was 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 the CVE record for CVE-2026-40393 published?
The CVE record for CVE-2026-40393 was published on April 12, 2026. That is the record's publication date; the vulnerability itself may have been made public earlier. EchelonGraph's copy of the record carries a last-modified date of October 26, 2026; the record at its source may have been updated since.
Is CVE-2026-40393 actively exploited?
CVE-2026-40393 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.4% probability of exploitation in the next 30 days (36th percentile of EPSS-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?
A fix for CVE-2026-40393 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-40393 are linked in the Vendor Advisories panel on this page.

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