CVE-2026-84761

The LiteSpeed Cache plugin for WordPress is vulnerable to Reflected Cross-Site Scripting via the 'esi' parameter in all versions up to and including 7.9 due to insufficient input sanitization and output escaping. This allows unauthenticated attackers to inject arbitrary web scripts that execute if they can trick a user into clicking a link. Exploitation requires a validly signed 'esi' value in the GET query string and a separate attacker-controlled 'esi' payload as a POST body field, relying on PHP's default $_REQUEST merge order.

The LiteSpeed Cache plugin for WordPress is vulnerable to Stored Cross-Site Scripting via crafted `<img>` tag attributes in all versions up to, and including, 7.7. This is due to a flawed regular expression used to strip `width` and `height` attributes from images when the "Lazy Load Images" and "Add Missing Sizes" features are enabled.

The LiteSpeed Cache plugin for WordPress up to version 7.8.1 is vulnerable to Stored Cross-Site Scripting via Comment Content. Insufficient input sanitization and output escaping allow unauthenticated attackers to inject arbitrary web scripts that execute when a user accesses an injected page. A payload crafted from decimal numeric character references bypasses WordPress's wp_kses sanitization.

The LiteSpeed Cache plugin for WordPress is vulnerable to Reflected Cross-Site Scripting via URLs in all versions up to, and including, 7.5.0.1 due to insufficient input sanitization and output escaping. This allows unauthenticated attackers to inject arbitrary web scripts that execute if they can trick a user into performing an action such as clicking a link.