LiteSpeed Cache <= 7.7 - Unauthenticated Stored Cross-Site Scripting via QUIC.cloud CCSS/UCSS REST API Endpoints
Summary
| CVE | CVE-2026-3375 |
|---|---|
| State | PUBLISHED |
| Assigner | Wordfence |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-05-27 08:16:40 UTC |
| Updated | 2026-05-27 14:50:47 UTC |
| 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. |
Risk And Classification
Primary CVSS: v3.1 7.2 HIGH from [email protected]
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N
EPSS: 0.000650000 probability, percentile 0.202380000 (date 2026-05-27)
Problem Types: CWE-79 | CWE-79 CWE-79 Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
| Version | Source | Type | Score | Severity | Vector |
|---|---|---|---|---|---|
| 3.1 | [email protected] | Primary | 7.2 | HIGH | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N |
| 3.1 | CNA | DECLARED | 7.2 | HIGH | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N |
CVSS v3.1 Breakdown
Attack Vector
NetworkAttack Complexity
LowPrivileges Required
NoneUser Interaction
NoneScope
ChangedConfidentiality
LowIntegrity
LowAvailability
NoneCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|---|---|---|---|
| CNA | Litespeedtech | LiteSpeed Cache | affected 7.7 semver | Not specified |
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| plugins.trac.wordpress.org/browser/litespeed-cache/trunk/src/router.cls.php | [email protected] | plugins.trac.wordpress.org | |
| www.wordfence.com/threat-intel/vulnerabilities/id/40fa29f5-525a-4986-91f9-0210a... | [email protected] | www.wordfence.com | |
| plugins.trac.wordpress.org/browser/litespeed-cache/trunk/src/rest.cls.php | [email protected] | plugins.trac.wordpress.org | |
| plugins.trac.wordpress.org/browser/litespeed-cache/trunk/src/optimize.cls.php | [email protected] | plugins.trac.wordpress.org | |
| plugins.trac.wordpress.org/browser/litespeed-cache/trunk/src/css.cls.php | [email protected] | plugins.trac.wordpress.org | |
| plugins.trac.wordpress.org/browser/litespeed-cache/trunk/src/cloud.cls.php | [email protected] | plugins.trac.wordpress.org | |
| plugins.trac.wordpress.org/changeset/3473912 | [email protected] | plugins.trac.wordpress.org | |
| plugins.trac.wordpress.org/browser/litespeed-cache/trunk/src/css.cls.php | [email protected] | plugins.trac.wordpress.org | |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
Vendor Comments And Credit
Discovery Credit
CNA: Osvaldo Noe Gonzalez Del Rio (en)
Additional Advisory Data
| Source | Time | Event |
|---|---|---|
| CNA | 2026-02-28T01:14:46.000Z | Vendor Notified |
| CNA | 2026-05-26T00:00:00.000Z | Disclosed |
There are currently no legacy QID mappings associated with this CVE.