Buffer overflow in Mesa3d Mesa
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.
Vulnerability class: Buffer Overflow
Published · last modified .
CVSS v3 metric
CVSS v3 base score 8.1 (High). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H.
EPSS exploit prediction
EPSS: 0.006 (47.4th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 47th percentile — 47.4% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.004 · newest: 0.006 · change: +0.002
Affected products
- Mesa3d Mesa — versions 0, 26.0.0
Weakness classification (CWE)
References
- lists.freedesktop.org/archives/mesa-dev/2026-February/226597.html (Mailing List, Issue Tracking)
- gitlab.freedesktop.org/mesa/mesa/-/merge_requests/39866 (Issue Tracking)
- af854a3a-2127-422b-91ae-364da2661108
Frequently asked questions
- What is CVE-2026-40393?
- CVE-2026-40393 is a high-severity vulnerability in Mesa3d Mesa, classified under Out-of-bounds Write. CVSS score: 8.1/10. Published 2026-04-12.
- How severe is CVE-2026-40393?
- High severity. CVSS v3 base score is 8.1 out of 10.