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Fencer Vulns
high 8.1

CVE-2026-40393 json

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 depe…

published 2026-04-12 6 mo ago modified 2026-10-26 13 d ago also EUVD-2026-21737

cvss
8.1
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.4%
EPSS 0.4% chance of exploitation in 30 days, percentile 37%
public exploits
0
none known

Summary

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.

Patch / fix

  • mesa3d Mesa 25.3.6, 26.0.1
  • mesa Debian 12 22.3.6-1+deb12u2
  • mesa Debian 13 25.0.7-2+deb13u1
  • mesa Debian 14 26.0.1-1

debian advisories DEBIAN-CVE-2026-40393

  • mesa Ubuntu 22.04 LTS 23.2.1-1ubuntu3.1~22.04.4
  • mesa Ubuntu 24.04 LTS 25.2.8-0ubuntu0.24.04.2
  • mesa Ubuntu 25.10 25.2.8-0ubuntu0.25.10.2

ubuntu advisories UBUNTU-CVE-2026-40393

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • Mesa SLE Micro 5.2 20.2.4-150300.59.12.1

suse advisories SUSE-SU-2026:1343-1

  • mesa Azure Linux 3.0 24.0.1-8

azure linux advisories AZL-82688

Azure Linux vulnerability data, Copyright (c) Microsoft Corporation, from https://github.com/microsoft/AzureLinuxVulnerabilityData via OSV, under the MIT licence; changed: normalised to fixed package versions per release. MIT

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
total
Assessed
6 mo ago

Exploit prediction

0.43% chance of exploitation in the next 30 days, higher than 37% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 8.1 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
NVD 3.1 9.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Affected products

  • mesa3d Mesa

Classification

Weakness

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.