Description
Mattermost Confluence plugin version <1.7.0 fails to properly escape user-controlled display names in HTML template rendering which allows authenticated Confluence users with malicious display names to execute arbitrary JavaScript in victim browsers via sending a specially crafted OAuth2 connection link that, when visited, renders the attacker's display name without proper sanitization. Mattermost Advisory ID: MMSA-2025-00557
Problem types
CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
Product status
Any version before 1.7.0
1.7.0
Credits
daw10
References
mattermost.com/security-updates (MMSA-2025-00557)