CVE-2026-2458

Published: Mar 16, 2026Modified: Jun 17, 2026

4.3

Vector

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

Exploitability: 2.8 / Impact: 1.4

Source: responsibledisclosure@mattermost.com (Secondary)

Description

Mattermost versions 11.3.x <= 11.3.0, 11.2.x <= 11.2.2, 10.11.x <= 10.11.10 fail to properly validate team membership when searching channels which allows a removed team member to enumerate all public channels within a private team via the channel search API endpoint.. Mattermost Advisory ID: MMSA-2025-00568

Affected (3)

Products: Mattermost: Mattermost Server

Mattermost

1 product

Mattermost Server

Configuration A

3 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 11.3.1

Related CWEs

CWE-862

Missing Authorization

The product does not perform an authorization check when an actor attempts to access a resource or perform an action.

References (1)

https://mattermost.com/security-updates

Source: responsibledisclosure@mattermost.com

Vendor Advisory

Timeline

No history available yet.