CVE-2017-18921: Mattermost Server

Medium severity, CVSS 6.1. EPSS: 0.7% chance of exploitation in the next 30 days.

An issue was discovered in Mattermost Server before 3.6.0 and 3.5.2. XSS can occur via a link on an error page.

Affected products

• Mattermost Mattermost Server: before 3.5.2 (fixed in 3.5.2)

Published 2020-06-19. Last modified 2026-06-17.