WordPress security changelog
HIGH CVE-2026-13354 Deferred

Asset CleanUp comment content becomes script when CSS combining is enabled

Unauthenticated comment content can become stored script through insufficient sanitization and output escaping when combine_loaded_css is enabled. A user must view affected output for browser execution. The export does not disclose the vulnerable rendering function, precise injected field or whether comment approval is required; it does not establish a moderation bypass. Authoritative affected range: <= 1.4.0.5.

CVE / CNA score 7.2 CVSS 3.1 · security@wordfence.com
NVD score Pending NVD has not published its own CVSS assessment.
Component
Asset CleanUp: Page Speed Booster
Plugin slug
wp-asset-clean-up
Affected
<= 1.4.0.5
Safe version
See mitigation notes
Published
Sep 19, 2026
Weakness
CWE-79 — Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')

This CVE was published Sep 19, 2026 and is one of 7 known issues for this plugin.

What to do

Update, patch or deactivate.

This archive could not verify a fixed version from the official author release notes reviewed on 2026-10-13. Disable the affected feature or component where practical until remediation for the deployed configuration is established. . Disable combine_loaded_css or the affected comment-rendering path until updated. Treat comment markup as untrusted through CSS-combination transformations and escape final output; remove malicious stored comments. Official author release notes: https://wordpress.org/plugins/wp-asset-clean-up/.

No confirmed safe version is listed. Consider a vendor-supported patch or temporarily restricting the affected functionality while you assess the risk.

Deactivate only when warranted by your risk profile, or when advised by your hosting provider in the limited circumstances where the vulnerability cannot otherwise be mitigated. If you’re unsure which action is appropriate, contact Fused or your hosting provider for guidance.

Source record

Technical description

The Asset CleanUp: Page Speed Booster plugin for WordPress is vulnerable to Stored Cross-Site Scripting via Comment Content in all versions up to, and including, 1.4.0.5 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. This is only exploitable on instances where combine_loaded_css has been enabled.

CVE / CNA vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N

References

Primary and upstream sources