CVE-2023-5522: Mattermost

Medium severity, CVSS 4.3. EPSS: 0.4% chance of exploitation in the next 30 days.

Mattermost Mobile fails to limit the maximum number of Markdown elements in a post allowing an attacker to send a post with hundreds of emojis to a channel and freeze the mobile app of users when viewing that particular channel. 

Affected products

• Mattermost Mattermost: before 2.8.0 (fixed in 2.8.0)

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