CVE-2026-40393: CWE-787 Out-of-bounds Write in mesa3d Mesa
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.
AI Analysis
Technical Summary
This vulnerability (CWE-787) in Mesa before 25.3.6 and 26 before 26.0.1 arises because the size of memory allocated via alloca depends on untrusted input, causing out-of-bounds memory access in the WebGPU component. The CVSS 3.1 score is 8.1, indicating a high severity with network attack vector, high complexity, no privileges or user interaction required, and impacts on confidentiality, integrity, and availability. No official patch or remediation level is currently documented, and no known exploits are reported in the wild.
Potential Impact
Successful exploitation can lead to out-of-bounds memory writes, potentially allowing an attacker to corrupt memory, cause crashes, or execute arbitrary code. The vulnerability impacts confidentiality, integrity, and availability of the affected system.
Mitigation Recommendations
Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until an official fix is released, avoid processing untrusted WebGPU content with affected Mesa versions. Monitor vendor channels for updates and apply patches once available.
CVE-2026-40393: CWE-787 Out-of-bounds Write in mesa3d Mesa
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 v3.1
Score 8.1high
Affected software
Run on your own infrastructure? Check whether these packages are installed with threat-finder — our free open-source scanner.
Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
This vulnerability (CWE-787) in Mesa before 25.3.6 and 26 before 26.0.1 arises because the size of memory allocated via alloca depends on untrusted input, causing out-of-bounds memory access in the WebGPU component. The CVSS 3.1 score is 8.1, indicating a high severity with network attack vector, high complexity, no privileges or user interaction required, and impacts on confidentiality, integrity, and availability. No official patch or remediation level is currently documented, and no known exploits are reported in the wild.
Potential Impact
Successful exploitation can lead to out-of-bounds memory writes, potentially allowing an attacker to corrupt memory, cause crashes, or execute arbitrary code. The vulnerability impacts confidentiality, integrity, and availability of the affected system.
Mitigation Recommendations
Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until an official fix is released, avoid processing untrusted WebGPU content with affected Mesa versions. Monitor vendor channels for updates and apply patches once available.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- mitre
- Date Reserved
- 2026-04-12T18:49:18.544Z
- Cvss Version
- 3.1
- State
- PUBLISHED
- Remediation Level
- null
Threat ID: 69dbefa382d89c981fa9bf0a
Added to database: 04/12/2026, 19:16:51 UTC
Last enriched: 07/14/2026, 08:15:30 UTC
Last updated: 07/31/2026, 19:22:58 UTC
Views: 202
Community Reviews
0 reviewsCrowdsource mitigation strategies, share intel context, and vote on the most helpful responses. Sign in to add your voice and help keep defenders ahead.
Want to contribute mitigation steps or threat intel context? Sign in or create an account to join the community discussion.
Actions
Updates to AI analysis require Pro Console access. Upgrade inside Console → Billing.
Need more coverage?
Upgrade to Pro Console for AI refresh and higher limits.
For incident response and remediation, OffSeq services can help resolve threats faster.
Latest Threats
Check if your credentials are on the dark web
Instant breach scanning across billions of leaked records. Free tier available.