CVE-2026-40393 Mesa3d CVE debrief

Who should care

Users of Mesa, particularly those using WebGPU, should be aware of this vulnerability. It may allow attackers to access sensitive data or execute arbitrary code. Affected operators, platforms, vulnerability-management, and security teams should review official advisories and assess their deployments.

Technical summary

The vulnerability arises from the WebGPU implementation in Mesa, where the allocation of data depends on an untrusted party. This can lead to out-of-bounds memory access, potentially allowing attackers to exploit the vulnerability. The issue affects Mesa versions before 25.3.6 and 26 before 26.0.1. Users should review and monitor WebGPU usage in their applications and consider implementing additional security measures, such as memory access controls.

Defensive priority

High priority should be given to updating Mesa to a secure version, as this vulnerability has been publicly disclosed and has a high CVSS score.

Recommended defensive actions

• Update Mesa to version 25.3.6 or later, or 26.0.1 or later.
• Review and monitor WebGPU usage in your applications.
• Consider implementing additional security measures, such as memory access controls.
• Confirm whether affected product deployments exist in managed environments and assign an owner for follow-up.
• Review compensating controls for exposed systems while remediation is scheduled and verified.
• Check relevant monitoring, detection, and logs for exposed assets that need extra review.
• Track exceptions, retest remediated assets, and close the item only after evidence is documented.

Evidence notes

The CVE record was published on 2026-04-12T19:16:20.797Z and was last modified on 2026-07-13T10:16:28.010Z. The NVD entry is currently Modified. This vulnerability affects Mesa versions before 25.3.6 and 26 before 26.0.1. Users should verify their deployments and review official advisories for affected scope and vendor guidance.

Sources and references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.