CVE-2026-3375
LiteSpeed Cache <= 7.7 - Unauthenticated Stored Cross-Site Scripting via QUIC.cloud CCSS/UCSS REST API Endpoints
- Published
- Updated
- Reserved
- Assigned by
- Wordfence
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.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| WordfenceCNA (assigner) | 3.1 | High7.2 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N |
| NVDNVD · Deferred | 3.1 | High7.2 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N |
- EPSS (exploitation in 30 days)
- 0.36% · top 70% of all CVEs (6 Nov 2026)
- CISA SSVC
- Exploitation: none · Automatable: yes · Technical impact: partial
The list uses the assigner's score when there is one, then CISA's, then NVD's: High 7.2.
Weakness
Affected products
litespeedtech · LiteSpeed Cache
- affected ≤ 7.7
References (8)
- https://www.wordfence.com/threat-intel/vulnerabilities/id/40fa29f5-525a-4986-91f9-0210a7594e46?source=cve (opens in a new tab)
- https://plugins.trac.wordpress.org/browser/litespeed-cache/trunk/src/rest.cls.php#L108 (opens in a new tab)
- https://plugins.trac.wordpress.org/browser/litespeed-cache/trunk/src/cloud.cls.php#L2085 (opens in a new tab)
- https://plugins.trac.wordpress.org/browser/litespeed-cache/trunk/src/css.cls.php#L401 (opens in a new tab)
- https://plugins.trac.wordpress.org/browser/litespeed-cache/trunk/src/css.cls.php#L595 (opens in a new tab)
- https://plugins.trac.wordpress.org/browser/litespeed-cache/trunk/src/optimize.cls.php#L477 (opens in a new tab)
- https://plugins.trac.wordpress.org/browser/litespeed-cache/trunk/src/router.cls.php#L732 (opens in a new tab)
- https://plugins.trac.wordpress.org/changeset/3473912/ (opens in a new tab)
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://trackcve.app/cve/CVE-2026-3375)Record last updated .