CVE-2026-40393: 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.

Overview

Severity
High (CVSS 8.1)
CVSS Vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
Exploit Status
Not Exploited
Patch Tuesday
2026-Apr
Released
2026-04-14
Last Updated
2026-08-23
EPSS Score
0.43% (percentile: 36.4%)

Affected Products (3)

Open Source Software

  • azl3 mesa 24.0.1-6 on Azure Linux 3.0
  • cbl2 mesa 21.0.0-4 on CBL Mariner 2.0

Other

  • 21221-21692

Revision History

  • 2026-04-14: Information published.
  • 2026-04-17: Information published.
  • 2026-04-18: Information published.
  • 2026-08-23: Information published.