CVE-2006-4271: Jelsoft vBulletin

High severity, CVSS 7.5. EPSS: 2.1% chance of exploitation in the next 30 days.

PHP remote file inclusion vulnerability in install/upgrade_301.php in Jelsoft vBulletin 3.5.4 allows remote attackers to execute arbitrary PHP code via a URL in the step parameter. NOTE: the vendor has disputed this vulnerability, saying "The default vBulletin requires authentication prior to the usage of the upgrade system.

Affected products

• Jelsoft vBulletin: version 3.5.4 only

Published 2006-08-21. Last modified 2026-06-16.