Mattermost Confluence plugin doesn't properly escape user-controlled display names in HTML template rendering
High severity
GitHub Reviewed
Published
Feb 6, 2026
to the GitHub Advisory Database
•
Updated Feb 6, 2026
Package
Affected versions
< 1.7.0
Patched versions
1.7.0
Description
Published by the National Vulnerability Database
Feb 6, 2026
Published to the GitHub Advisory Database
Feb 6, 2026
Reviewed
Feb 6, 2026
Last updated
Feb 6, 2026
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
References