CVE-2023-39777: vBulletin

Medium severity, CVSS 5.4. EPSS: 0.4% chance of exploitation in the next 30 days.

A cross-site scripting (XSS) vulnerability in the Admin Control Panel of vBulletin 5.7.5 and 6.0.0 allows attackers to execute arbitrary web scripts or HTML via the /login.php?do=login url parameter.

Affected products

• vBulletin vBulletin: up to and including 6.0.0

Published 2023-09-16. Last modified 2026-06-17.