CVE-2026-3116

Medium

Description

Mattermost Plugins versions <=11.4 11.0.4 11.1.3 11.3.2 10.11.11.0 fail to validate incoming request size which allows an authenticated attacker to cause service disruption via the webhook endpoint. Mattermost Advisory ID: MMSA-2026-00589

SeverityMedium

CVSS4.9

Exploit probability—

Product

Mattermost Server

PublishedMar 26, 2026

First seenMar 26, 2026

Weakness typeCWE-400Uncontrolled resource consumption

How to fix

Update

mattermost mattermost_server10.11.12, 11.2.4, 11.3.2, 11.4.1 or later

Vendor advisories

mattermost.com/security-updates

Affected products

Product	Affected versions	Fixed in
mattermost mattermost_server	10.11.0 ≤ v < 10.11.12, 11.2.0 ≤ v < 11.2.4, 11.3.0 ≤ v < 11.3.2, 11.4.0 ≤ v < 11.4.1	10.11.12, 11.2.4, 11.3.2, 11.4.1

Check your version

Choose the product and enter the version you run to see whether it falls in the affected range.

In the Intelligence 360 plan

Attack Surface Management

See the assets tied to your domains, the technologies they run and known vulnerabilities in one list.