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Microsoft Security Response CenterCVE-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.

HighVendor CVSS 8.1 / 10 1 CVE Published Apr 14, 2026 at 1:01 AM UTC

Summary

Mariner

Products covered

  • azl3 mesa 24.0.1-6 on Azure Linux 3.0

  • cbl2 mesa 21.0.0-4 on CBL Mariner 2.0

  • cbl2 mesa 21.0.0-4 on CBL-Mariner 2.0

Remediation

CBL-Mariner Releases Release Notes

Vendor-listed fixes

  • 24.0.1-8

CVEs in this advisory 1

Update history

What changed in later vendor updates

SecurityAlert records field-level changes from the point we begin following a bulletin. Earlier vendor changes may not have a field-by-field record.

    • The vendor changed the advisory title.
    • Added affected products: cbl2 mesa 21.0.0-4 on CBL-Mariner 2.0.
    • The vendor changed its remediation guidance.

Updates

  1. Published by Microsoft Security Response Center

    The publication date reported by the vendor.

  2. Updated by Microsoft Security Response Center

    The vendor changed the advisory after it was first published.

  3. Added to SecurityAlert

    We collected the advisory from the official source.

  4. Confirmed at the source

    Our collector saw this advisory during a later source check.