Autoptimize: Cross-site scripting
Autoptimize is affected by cross-site scripting. Exploitation requires at least contributor-level access. Injected script can execute in the affected site's origin when the vulnerable output is viewed.
- Component
- Autoptimize
- Plugin slug
autoptimize- Affected
- See vendor advisory
- Safe version
- See mitigation notes
- Published
- Mar 21, 2026
This CVE was published Mar 21, 2026 and is one of 11 known issues for this plugin.
Update, patch or deactivate.
Update Autoptimize to a release outside the affected range, or disable and remove it until a fixed version is available.
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.
Technical description
The Autoptimize plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the lazy-loading image processing in all versions up to, and including, 3.1.14. This is due to the use of an overly permissive regular expression in the `add_lazyload` function that replaces all occurrences of `\ssrc=` in image tags without limiting to the actual attribute. This makes it possible for authenticated attackers, with Contributor-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page by crafting an image tag where the `src` URL contains a space followed by `src=`, causing the regex to break the HTML structure and promote text inside attribute values into executable HTML attributes.
CVE / CNA vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N