CVE-2021-47934: Mybb Timeline Plugin

Medium severity, CVSS 5.3. EPSS: 0.2% chance of exploitation in the next 30 days.

MyBB Timeline Plugin 1.0 contains cross-site scripting vulnerabilities that allow attackers to inject malicious scripts through thread titles, post content, and user profile fields like Location and Bio. Attackers can also exploit a cross-site request forgery vulnerability in the timeline.php profile action to change a user's cover picture by crafting malicious forms that execute when victims visit affected profiles.

Affected products

• Mybb Mybb Timeline Plugin: version 1.0 only

Published 2026-05-16. Last modified 2026-06-17.