Cybersecurity researchers have disclosed a critical security flaw in the LiteSpeed Cache plugin for WordPress that could permit unauthenticated users to gain administrator privileges.

“The plugin suffers from an unauthenticated privilege escalation vulnerability which allows any unauthenticated visitor to gain Administrator level access after which malicious plugins could be uploaded and installed,” Patchstack’s Rafie Muhammad said in a Wednesday report.

The vulnerability, tracked as CVE-2024-28000 (CVSS score: 9.8), has been patched in version 6.4 of the plugin released on August 13, 2024. It impacts all versions of the plugin, including and prior to 6.3.0.1.

LiteSpeed Cache is one of the most widely used caching plugins in WordPress with over five million active installations.