6.5

CVE-2026-9571

Deactivated user accounts can continue to obtain valid OAuth access tokens via refresh token grant in Mattermost

Mattermost versions 11.7.x <= 11.7.2, 11.6.x <= 11.6.4, 10.11.x <= 10.11.19 fail to invalidate OAuth refresh tokens upon user account deactivation, which allows a deactivated user or an attacker in possession of a valid refresh token to obtain new functional access tokens via the OAuth refresh token grant endpoint.. Mattermost Advisory ID: MMSA-2026-00680
Daten sind bereitgestellt durch National Vulnerability Database (NVD)
Mattermost ≫ Mattermost Server Version >= 10.11.0 < 10.11.20
Mattermost ≫ Mattermost Server Version >= 11.6.0 < 11.6.5
Mattermost ≫ Mattermost Server Version >= 11.7.0 < 11.7.3
VulnDex Vulnerability Enrichment
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Zu dieser CVE wurde keine Warnung gefunden.
EPSS Metriken
Typ Quelle Score Percentile
EPSS FIRST.org 0.17% 0.07
CVSS Metriken
Quelle Base Score Exploit Score Impact Score Vector String
NIST 6.5 2.8 3.6
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N
responsibledisclosure@mattermost.com 5.9 0.7 5.2
CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:N
CWE-305 Authentication Bypass by Primary Weakness

The authentication algorithm is sound, but the implemented mechanism can be bypassed as the result of a separate weakness that is primary to the authentication error.

https://mattermost.com/security-updates
Vendor Advisory