CVE-2020-19049: Mybb

Medium severity, CVSS 5.4. EPSS: 0.7% chance of exploitation in the next 30 days.

Cross Site Scripting (XSS) in MyBB v1.8.20 allows remote attackers to inject arbitrary web script or HTML via the "Description" field found in the "Add New Forum" page by doing an authenticated POST HTTP request to '/Upload/admin/index.php?module=forum-management&action=add'.

Affected products

• Mybb Mybb: version 1.8.20 only

Published 2021-08-31. Last modified 2026-06-17.