CVE-2017-17672: vBulletin

Critical severity, CVSS 9.8. EPSS: 15.2% chance of exploitation in the next 30 days.

In vBulletin through 5.3.x, there is an unauthenticated deserialization vulnerability that leads to arbitrary file deletion and, under certain circumstances, code execution, because of unsafe usage of PHP's unserialize() in vB_Library_Template's cacheTemplates() function, which is a publicly exposed API. This is exploited with the templateidlist parameter to ajax/api/template/cacheTemplates.

Affected products

• vBulletin vBulletin: from 5.0.1, up to and including 5.3.3; version 5.0.0 only

Published 2017-12-14. Last modified 2026-06-17.