CVE-2017-18905: Mattermost Server

Medium severity, CVSS 5.3. EPSS: 0.8% chance of exploitation in the next 30 days.

An issue was discovered in Mattermost Server before 4.0.0, 3.10.2, and 3.9.2, when used as an OAuth 2.0 service provider, Session invalidation was mishandled.

Affected products

• Mattermost Mattermost Server: before 3.9.2 (fixed in 3.9.2); from 3.10.0, before 3.10.2 (fixed in 3.10.2)

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