WordPress security changelog
HIGH CVE-2026-3220 Deferred

Autoptimize, Clearfy Cache, Speed Optimizer: Cross-site scripting

Autoptimize, Clearfy Cache, Speed Optimizer is affected by cross-site scripting. The vulnerable path is reachable without authentication. Injected script can execute in the affected site's origin when the vulnerable output is viewed. The published affected range is < 3.1.15, < 2.4.2, < 7.7.9.

CVE / CNA score 8.8 CVSS 3.1 · 134c704f-9b21-4f2e-91b3-4a467353bcc0
NVD score Pending NVD has not published its own CVSS assessment.
Component
Autoptimize, Clearfy Cache, Speed Optimizer
Plugin slug
autoptimize
Affected
< 3.1.15, < 2.4.2, < 7.7.9
Safe version
3.1.15, 2.4.2, 7.7.9
Published
May 18, 2026
Weakness
CWE-79 — Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')

This CVE was published May 18, 2026 and is one of 11 known issues for this plugin.

Update, patch or deactivate.

Update Autoptimize, Clearfy Cache, Speed Optimizer to a release outside the affected range, or disable and remove it until a fixed version is available.

A safe version is available, so updating to that version or later is the preferred remediation. If an immediate update is not practical, consider a targeted application patch or temporarily restricting the affected functionality.

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.

Technical description

The Autoptimize WordPress plugin before 3.1.15, Clearfy Cache WordPress plugin before 2.4.2, Speed Optimizer WordPress plugin before 7.7.9 are vulnerable to unauthenticated Stored Cross-Site Scripting (XSS) due to a predictable replacement hash used during the HTML minification process and abusing a regular expression. This allows an attacker to inject arbitrary HTML attributes in the final HTML output by anticipating the placeholder format.

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

Primary and upstream sources