CVE-2026-3375

LiteSpeed Cache <= 7.7 - Unauthenticated Stored Cross-Site Scripting via QUIC.cloud CCSS/UCSS REST API Endpoints

HIGH
7.2
CVSS Score
Published: May 27, 2026 at 07:45 AM UTC
Updated: June 17, 2026 at 10:43 AM UTC
1 product affected across 1 vendorLiteSpeed Cache

Using LiteSpeed Cache by litespeedtech?

Get instant alerts when new vulnerabilities affect LiteSpeed Cache - before attackers find them.

Real-time alertsTrack your software stackFree plan available
Severity
HIGH7.2
Exploit prediction
EPSS 0.4%
SSVC
No known exploit

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.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

v ≤ 7.7

Remediation

No guide yet

No remediation guidance has been written for this CVE yet, and no fixed version or vendor advisory is recorded against it.

SSVC — Action Prioritization

SSVCNo known exploitAutomatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

7.2HIGHWordfence
Vector?

Quick Info

StatusDEFERRED
CWE
CWE-79

Get alerted

Stop reading CVE feeds looking for your own stack

Track the products you run and VulnTracker tells you when a new CVE affects them — with what is known about fixing it, and nothing about the rest.

Free plan, no card