CVE-2026-3375

High

Published: 27/05/2026(UTC)Translated: 15/06/2026(UTC)NVD NIST

Summary

The LiteSpeed Cache plugin for WordPress is vulnerable to Stored Cross-Site Scripting (XSS) via the /wp-json/litespeed/v1/notify_ccss and /wp-json/litespeed/v1/notify_ucss REST API endpoints in all versions up to and including 7.7. These endpoints accept CSS content from QUIC.cloud callback notifications and store it to disk without sanitization.

Risk Assessment

Attackers can inject arbitrary JavaScript into CCSS/UCSS content, potentially leading to user data theft or session hijacking. The risk is heightened when the WordPress site is behind a reverse proxy, load balancer, or CDN with certain configurations.

Recommendation

It is recommended to update the LiteSpeed Cache plugin to the latest version and implement additional security measures, such as content validation and access restrictions to the API endpoints.

Original NVD description (English source)

The LiteSpeed Cache plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the /wp-json/litespeed/v1/notify_ccss and /wp-json/litespeed/v1/notify_ucss REST API endpoints in all versions up to, and including, 7.7. These endpoints accept CSS content from QUIC.cloud callback notifications and store it to disk without sanitization. The stored content is later rendered inline frontend page loads without output escaping. The access control protecting these endpoints is IP-based validation that can potentially be bypassed when the WordPress site is deployed behind a reverse proxy, load balancer, or CDN with certain configurations. This makes it possible for unauthenticated attackers, under certain conditions, to inject arbitrary JavaScript into CCSS/UCSS content.