Description
Mattermost Desktop App versions <=6.1 6.0.1 5.4.13.0 fail to prevent server-rendered content from closing an underlying application view in the Mattermost Desktop App which allows a malicious server or plugin to crash the desktop client via invoking {{window.close()}} in the renderer context, leading to a denial of service condition at the client level. Mattermost Advisory ID: MMSA-2026-00633
Problem types
CWE-754: Improper Check for Unusual or Exceptional Conditions
Product status
Any version
Any version
6.2.0
6.1.1.0
5.13.5.0
Credits
Devin Binnie
References
mattermost.com/security-updates (MMSA-2026-00633)