CVE-2023-5333: Mattermost Server

Medium severity, CVSS 6.5. EPSS: 0.6% chance of exploitation in the next 30 days.

Mattermost fails to deduplicate input IDs allowing a simple user to cause the application to consume excessive resources and possibly crash by sending a specially crafted request to /api/v4/users/ids with multiple identical IDs.

Affected products

• Mattermost Mattermost Server: before 7.8.11 (fixed in 7.8.11); from 8.0.0, before 8.0.3 (fixed in 8.0.3); from 8.1.0, before 8.1.2 (fixed in 8.1.2)

Published 2023-10-09. Last modified 2026-06-17.