CVE-2018-21261: Mattermost Server

Medium severity, CVSS 4.3. EPSS: 0.6% chance of exploitation in the next 30 days.

An issue was discovered in Mattermost Server before 4.8.1, 4.7.4, and 4.6.3. An e-mail invite accidentally included the team invite_id, which leads to unintended excessive invitation privileges.

Affected products

• Mattermost Mattermost Server: from 4.6.0, before 4.6.3 (fixed in 4.6.3); from 4.7.0, before 4.7.4 (fixed in 4.7.4); from 4.8.0, before 4.8.1 (fixed in 4.8.1)

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