CVE-2026-18978

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.

Predictions

Heuristic predictions, AS-IS, for prioritization only.

Mitigations

References

• https://plugins.trac.wordpress.org/browser/litespeed-cache/trunk/src/media.cls.php#L1317
• https://plugins.trac.wordpress.org/browser/litespeed-cache/trunk/src/media.cls.php#L1358
• https://plugins.trac.wordpress.org/browser/litespeed-cache/trunk/src/media.cls.php#L1405
• https://plugins.trac.wordpress.org/browser/litespeed-cache/trunk/src/media.cls.php#L777
• https://plugins.trac.wordpress.org/changeset/3635849/litespeed-cache/trunk/src/media.cls.php
• https://plugins.trac.wordpress.org/changeset?old_path=%2Flitespeed-cache/tags/7.8.1&new_path=%2Flitespeed-cache/tags/7.9
• https://www.wordfence.com/threat-intel/vulnerabilities/id/0b045f3d-8412-4e35-b369-2b485639274d?source=cve

CWEs

CWE-79