CVE-2026-18978

LiteSpeed Cache <= 7.8.1 - Unauthenticated Stored Cross-Site Scripting via Comment Content

HIGH
7.2
CVSS Score
Published: August 28, 2026 at 03:39 AM UTC
Updated: August 28, 2026 at 08:17 PM UTC
1 product affected across 1 vendorLiteSpeed Cache

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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 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. &#34;, &#60;, &#62;) placed inside an allowed element such as &lt;code&gt; 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.

Affected

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

v ≤ 7.8.1

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

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