9.8

CVE-2026-40393: mesa3d mesa Out-of-bounds Write

CVSS: 9.8v3.1CriticalModified
AliasesSUSE-SU-2026:1343-1UBUNTU-CVE-2026-40393USN-8427-1
Published 12-04-2026Last modified 13-07-2026
Open JSON

Vulnerability summary

CVE-2026-40393 is a critical (CVSS 9.8) Out-of-bounds Write vulnerability in mesa3d mesa. EPSS estimates a 0.61% chance of exploitation in the next 30 days, higher than 48.4% of scored vulnerabilities.

Overall risk
70/100
0100
High · default modelHow is this calculated?
CVSS score
9.8/10
010
Critical · v3.1 (NVD)
EPSS score
0.61%
0%100%
Low · +0.19 pp in 30 days
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded

Timeline

  1. 12-04-2026
    PublishedVulnerability first disclosed.
  2. 13-07-2026
    Last modifiedVulnerability information updated.

Description

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 metrics

4 scores · 4 sources · 1 version

EPSS trend

Probability

0.61%

Chance of exploitation in the next 30 days

Percentile

48%

Versus all other CVEs

30-day change

+0.19 pp

From 0.43% on 19-09-2026

19-09-202619-10-2026
EPSS score
0.61%

Known exploited

Compare KEV catalogs

Not in any of the 3 tracked catalogs.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Debian1 product
  • mesa< 22.3.6-1+deb12u2 | < 25.0.7-2+deb13u1 | < 26.0.1-1
Mesa3d1 product
  • mesa≥ 26.0.0, < 26.0.1 | < 25.3.6 | 26.0.0
Suse1 product
  • Mesa&distro=SUSE Linux Enterprise Micro 5.2< 20.2.4-150300.59.12.1
Ubuntu1 product
  • mesaAll versions (No fix recorded) | < 23.2.1-1ubuntu3.1~22.04.4 | < 25.2.8-0ubuntu0.24.04.2 | < 25.2.8-0ubuntu0.25.10.2

4 vendors · 4 products

References

11 links
Show all 11 references