CVE-2026-3117

Medium

Description

Mattermost Plugins versions <=11.5 11.1.5 10.13.11 11.3.4.0 fail to properly check for permissions when processing commands in the Gitlab plugin which allows normal users to uninstall instances or setup webhook connections via the {{gitlab instance {option}}} or the {{/gitlab webhook {option}}} commands. Mattermost Advisory ID: MMSA-2026-00600

SeverityMedium

CVSS6.5

Exploit probability—

Product

Mattermost Server

PublishedMay 18, 2026

First seenMay 18, 2026

Weakness typeCWE-862Missing authorization

How to fix

Vendor advisories

mattermost.com/security-updates

Affected products

Product	Affected versions	Fixed in
mattermost mattermost_server	10.13.0 ≤ v ≤ 10.13.11, 11.1.0 ≤ v ≤ 11.1.5, 11.3.0 ≤ v ≤ 11.3.4	—

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