CVE-2026-13411

Medium

Description

Mattermost versions 11.7.x <= 11.7.11 fail to validate null elements when decoding playbook import conditions which allows an authenticated attacker to crash the Playbooks plugin instance-wide via a crafted import request containing a null condition. Mattermost Advisory ID: MMSA-2026-00709

SeverityMedium

CVSS4.3

Exploit probability—

Product

Mattermost Server

PublishedOct 22, 2026

First seenOct 22, 2026

Weakness typeCWE-754CWE-754

How to fix

Update

mattermost mattermost_server11.7.12 or later

Vendor advisories

mattermost.com/security-updates

Affected products

Product	Affected versions	Fixed in
mattermost mattermost_server	11.7.0 ≤ v < 11.7.12	11.7.12

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