CVE-2020-14458: Mattermost Server

High severity, CVSS 7.5. EPSS: 1.1% chance of exploitation in the next 30 days.

An issue was discovered in Mattermost Server before 5.19.0. Attackers can discover private channels via the "get channel by name" API, aka MMSA-2020-0004.

Affected products

• Mattermost Mattermost Server: before 5.19.0 (fixed in 5.19.0)

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