CVE-2025-3230: Bypass of System Admin User Deactivation Controls for Personal Access Tokens in Mattermost Server

Severity: medium (CVSS 5.4 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2025-05-30 · updated 2026-06-17
Weakness: CWE-303

Description

Mattermost versions 10.7.x <= 10.7.0, 10.6.x <= 10.6.2, 10.5.x <= 10.5.3, 9.11.x <= 9.11.12 fails to properly invalidate personal access tokens upon user deactivation, allowing deactivated users to maintain full system access by exploiting access token validation flaws via continued usage of previously issued tokens.

Affected products

Mattermost: from 9.11.0 before 9.11.13; from 10.5.0 before 10.5.4; from 10.6.0 before 10.6.3; from 10.7.0 before 10.7.1 — fixed in 10.5.4, 10.6.3, 10.7.1, 9.11.13

How to fix

Upgrade to a fixed version: Mattermost 10.5.4, 10.6.3, 10.7.1, 9.11.13. Check the vendor advisory for mitigations.

References

https://mattermost.com/security-updates

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