CVE-2026-40393
9.8
CRITICAL
CVSS 3.1
EPSS 0.43%
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.
How to fix CVE-2026-40393
To remediate CVE-2026-40393, upgrade the affected package to a fixed version below.
- Debian/mesa—upgrade to 20.3.5-1+deb11u1 or later
Is CVE-2026-40393 being exploited?
Low — EPSS is 0.4%, meaning exploitation activity has not been observed at scale.
Affected packages (1)
- from 0, < 20.3.5-1+deb11u1
CVSS scores
| Source | Version | Severity | Vector |
|---|---|---|---|
| osv | CVSS 3.1 | CRITICAL9.8 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |