How severe is CVE-2026-40393?

CVE-2026-40393 has a CVSS 3.x base score of 8.1, rated high severity. It is exploitable over network with high attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2026-40393 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (27th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-40393?

CVE-2026-40393 primarily affects Mesa3d Mesa. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2026-40393?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

Does CVE-2026-40393 have an EU (EUVD) identifier?

Yes. CVE-2026-40393 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-21737.

When was CVE-2026-40393 published?

CVE-2026-40393 was published on 2026-04-12 and last updated on 2026-06-17.

CVE-2026-40393

CVE-2026-40393 is a high-severity vulnerability in Mesa3d Mesa with a CVSS 3.x base score of 8.1. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-787.

Key facts

Severity: High (CVSS 3.x base score 8.1)
EPSS exploit prediction: 0% (27th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-21737
Weakness: CWE-787
Affected product: Mesa3d Mesa
Published: 2026-04-12
Last modified: 2026-06-17

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.

Frequently asked questions

What is 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.
How severe is CVE-2026-40393?: CVE-2026-40393 has a CVSS 3.x base score of 8.1, rated high severity. It is exploitable over network with high attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2026-40393 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (27th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-40393?: CVE-2026-40393 primarily affects Mesa3d Mesa. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2026-40393?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
Does CVE-2026-40393 have an EU (EUVD) identifier?: Yes. CVE-2026-40393 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-21737.
When was CVE-2026-40393 published?: CVE-2026-40393 was published on 2026-04-12 and last updated on 2026-06-17.

References

Affected products (2)

cpe:2.3:a:mesa3d:mesa:*:*:*:*:*:*:*:*
cpe:2.3:a:mesa3d:mesa:26.0.0:*:*:*:*:*:*:*

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