CVE-2026-27659

Published: Mar 25, 2026Modified: Mar 26, 2026

4.6

Vector

CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:L/I:L/A:N

Exploitability: 2.1 / Impact: 2.5

Source: responsibledisclosure@mattermost.com (Secondary)

Description

Mattermost versions 11.2.x <= 11.2.2, 10.11.x <= 10.11.10, 11.4.x <= 11.4.0, 11.3.x <= 11.3.1 fail to properly validate CSRF tokens in the /api/v4/access_control_policies/{policy_id}/activate endpoint, which allows an attacker to trick an admin into changing access control policy active status via a crafted request.. Mattermost Advisory ID: MMSA-2026-00578

Affected (4)

Products: Mattermost: Mattermost Server

Mattermost

1 product

Mattermost Server

Configuration A

4 vulnerable

Vulnerable Software	Affected Versions
Mattermost Mattermost Server	From 10.11.0 to 10.11.11
Mattermost Mattermost Server	From 11.2.0 to 11.2.3
Mattermost Mattermost Server	From 11.3.0 to 11.3.2
Mattermost Mattermost Server	From 11.4.0 to 11.4.1

Related CWEs

CWE-352

Cross-Site Request Forgery (CSRF)

The web application does not, or can not, sufficiently verify whether a well-formed, valid, consistent request was intentionally provided by the user who submitted the request.

References (1)

https://mattermost.com/security-updates

Source: responsibledisclosure@mattermost.com

Vendor Advisory

Timeline

No history available yet.