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.

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History

Wed, 27 May 2026 09:45:00 +0000

Type Values Removed Values Added
First Time appeared Litespeedtech
Litespeedtech litespeed Cache
Wordpress
Wordpress wordpress
Vendors & Products Litespeedtech
Litespeedtech litespeed Cache
Wordpress
Wordpress wordpress

Wed, 27 May 2026 08:00:00 +0000

Type Values Removed Values Added
Description 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.
Title LiteSpeed Cache <= 7.7 - Unauthenticated Stored Cross-Site Scripting via QUIC.cloud CCSS/UCSS REST API Endpoints
Weaknesses CWE-79
References
Metrics cvssV3_1

{'score': 7.2, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N'}


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cve-icon MITRE

Status: PUBLISHED

Assigner: Wordfence

Published:

Updated: 2026-05-27T07:45:55.498Z

Reserved: 2026-02-28T00:59:32.665Z

Link: CVE-2026-3375

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-05-27T08:16:40.707

Modified: 2026-05-27T08:16:40.707

Link: CVE-2026-3375

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-05-27T09:30:27Z

Weaknesses