LiteSpeed Cache <= 7.8.1 - Unauthenticated Stored Cross-Site Scripting via Comment Content
Summary
| CVE | CVE-2026-18978 |
|---|---|
| State | PUBLISHED |
| Assigner | Wordfence |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-08-28 05:16:41 UTC |
| Updated | 2026-08-28 20:17:23 UTC |
| Description | The LiteSpeed Cache plugin for WordPress is vulnerable to Stored Cross-Site Scripting via Comment Content in all versions up to, and including, 7.8.1 due to insufficient input sanitization and output escaping. This makes it possible for unauthenticated attackers to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page. A comment payload crafted exclusively from decimal numeric character references (e.g. ", <, >) placed inside an allowed element such as <code> bypasses WordPress's wp_kses sanitization, as kses does not treat a data-settings="..." substring within text content as an HTML attribute, allowing the malicious payload to reach the vulnerable function. For this to be exploitable, the site must allow users with previously approved comments to write new comments, and the require_name_email setting must be disabled. |
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: 0.002740000 probability, percentile 0.193180000 (date 2026-08-31)
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] | Secondary | 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 7.8.1 semver | Not specified |
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| plugins.trac.wordpress.org/browser/litespeed-cache/trunk/src/media.cls.php | [email protected] | plugins.trac.wordpress.org | |
| plugins.trac.wordpress.org/changeset/3635849/litespeed-cache/trunk/src/media.cls.php | [email protected] | plugins.trac.wordpress.org | |
| plugins.trac.wordpress.org/browser/litespeed-cache/trunk/src/media.cls.php | [email protected] | plugins.trac.wordpress.org | |
| plugins.trac.wordpress.org/changeset | [email protected] | plugins.trac.wordpress.org | |
| plugins.trac.wordpress.org/browser/litespeed-cache/trunk/src/media.cls.php | [email protected] | plugins.trac.wordpress.org | |
| www.wordfence.com/threat-intel/vulnerabilities/id/0b045f3d-8412-4e35-b369-2b485... | [email protected] | www.wordfence.com | |
| plugins.trac.wordpress.org/browser/litespeed-cache/trunk/src/media.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: Jack Taylor (en)
Additional Advisory Data
| Source | Time | Event |
|---|---|---|
| CNA | 2026-08-05T16:50:13.000Z | Vendor Notified |
| CNA | 2026-08-27T15:19:36.000Z | Disclosed |
There are currently no legacy QID mappings associated with this CVE.