CVE-2020-14453: Mattermost Server

High severity, CVSS 7.5. EPSS: 0.6% chance of exploitation in the next 30 days.

An issue was discovered in Mattermost Server before 5.21.0. Socket read operations are not appropriately restricted, which allows attackers to cause a denial of service, aka MMSA-2020-0005.

Affected products

• Mattermost Mattermost Server: before 5.21.0 (fixed in 5.21.0)

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