CVE-2020-14459: Mattermost Server

High severity, CVSS 7.5. EPSS: 0.9% chance of exploitation in the next 30 days.

An issue was discovered in Mattermost Server before 5.19.0. Attackers can rename a channel and cause a collision with a direct message, aka MMSA-2020-0002.

Affected products

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

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