SEPTEMBER 18, 2026
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Case File

CVE-2026-9571

MEDIUM · CVSS 5.9 EPSS 0.17%

Source: NVD + CISA KEV + EPSS · Published 2026-07-13 · Last synced 2026-08-12

CyberRota Analysis

AI-Generated

Mattermost versions 11.7.x up to 11.7.2, 11.6.x up to 11.6.4, and 10.11.x up to 10.11.19 are vulnerable due to a failure to invalidate OAuth refresh tokens when user accounts are deactivated. This oversight allows deactivated users or attackers with valid refresh tokens to generate new access tokens, potentially leading to unauthorized access to sensitive data. Organizations using these Mattermost versions should prioritize patching to mitigate the risk of account takeover and unauthorized access.

CVE
CVE-2026-9571
Severity
MEDIUM
CVSS
5.9
EPSS
0.17%

Original NVD Description

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

Related CVEs

Other vulnerabilities affecting the same vendor(s)