On August 14, 2023, the Wordfence Threat Intelligence team identified and began the responsible disclosure process for a stored Cross-Site Scripting (XSS) vulnerability in LiteSpeed Cache plugin, which is actively installed on more than 4,000,000 WordPress websites, making it the most popular cache plugin. The vulnerability enables threat actors with contributor-level permissions or higher to inject malicious web scripts into pages using the plugin’s shortcode.
All WordFence customers are protected against any exploits targeting this vulnerability by the Wordfence firewall’s built-in Cross-Site Scripting protection.
WordFence contacted The LiteSpeed Cache Team on August 14, 2023, and we received a response on the same day. After providing full disclosure details, the developer team made a patch on August 16, 2023, and released it to the WordPress repository on October 10, 2023. We would like to commend the LiteSpeed Technologies for their prompt response and timely patch.
We urge users to update their sites with the latest patched version of LiteSpeed Cache, version 5.7 at the time of this writing, as soon as possible.