mesa3d Mesa up to 25.3.5/26.0.0 WebGPU out-of-bounds write

CVSS Meta Temp Score
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CTI Interest Score
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9.1$0-$5k0.00

Summaryinfo

A vulnerability classified as critical was found in mesa3d Mesa up to 25.3.5/26.0.0. This issue affects some unknown processing of the component WebGPU. The manipulation results in out-of-bounds write. This vulnerability is reported as CVE-2026-40393. The attack can be launched remotely. No exploit exists. Upgrading the affected component is advised.

Detailsinfo

A vulnerability, which was classified as very critical, was found in mesa3d Mesa up to 25.3.5/26.0.0. Affected is an unknown function of the component WebGPU. The manipulation with an unknown input leads to a out-of-bounds write vulnerability. CWE is classifying the issue as CWE-787. The product writes data past the end, or before the beginning, of the intended buffer. This is going to have an impact on confidentiality, integrity, and availability. CVE summarizes:

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.

The advisory is available at lists.freedesktop.org. This vulnerability is traded as CVE-2026-40393 since 04/12/2026. The exploitability is told to be easy. It is possible to launch the attack remotely. The exploitation doesn't require any form of authentication. The technical details are unknown and an exploit is not available. The structure of the vulnerability defines a possible price range of USD $0-$5k at the moment (estimation calculated on 07/13/2026).

The vulnerability scanner Nessus provides a plugin with the ID 306057 (Linux Distros Unpatched Vulnerability : CVE-2026-40393), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 25.3.6 or 26.0.1 eliminates this vulnerability. Applying a patch is able to eliminate this problem. The bugfix is ready for download at gitlab.freedesktop.org. The best possible mitigation is suggested to be upgrading to the latest version.

The vulnerability is also documented in the vulnerability database at Tenable (306057). If you want to get best quality of vulnerability data, you may have to visit VulDB.

Productinfo

Vendor

Name

Version

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 9.2
VulDB Meta Temp Score: 9.1

VulDB Base Score: 9.8
VulDB Temp Score: 9.4
VulDB Vector: 🔒
VulDB Reliability: 🔍

NVD Base Score: 9.8
NVD Vector: 🔒

CNA Base Score: 8.1
CNA Vector (MITRE): 🔒

CVSSv2info

AVACAuCIA
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VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Out-of-bounds write
CWE: CWE-787 / CWE-119
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

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Nessus ID: 306057
Nessus Name: Linux Distros Unpatched Vulnerability : CVE-2026-40393

Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Mesa 25.3.6/26.0.1
Patch: gitlab.freedesktop.org

Timelineinfo

04/12/2026 Advisory disclosed
04/12/2026 +0 days CVE reserved
04/12/2026 +0 days VulDB entry created
07/13/2026 +92 days VulDB entry last update

Sourcesinfo

Advisory: lists.freedesktop.org
Status: Confirmed

CVE: CVE-2026-40393 (🔒)
GCVE (CVE): GCVE-0-2026-40393
GCVE (VulDB): GCVE-100-357042

Entryinfo

Created: 04/12/2026 21:27
Updated: 07/13/2026 16:45
Changes: 04/12/2026 21:27 (65), 04/13/2026 16:13 (2), 07/13/2026 16:45 (11)
Complete: 🔍
Cache ID: 216::103

If you want to get best quality of vulnerability data, you may have to visit VulDB.

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