CVE-2026-3604 Cross-site scripting in WP SEO Structured Data Schema
Authenticated attackers can inject arbitrary scripts via a parameter, leading to script execution in victim browsers.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-3604?
CVE-2026-3604 is a medium-severity cross-site scripting vulnerability in kcseopro WP SEO Structured Data Schema, published on 12 May 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
The WP SEO Structured Data Schema plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the `_kcseo_ative_tab` parameter in all versions up to, and including, 2.8.1 due to insufficient input sanitization and output escaping. 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.
Weakness: CWE-79
Which versions are affected by CVE-2026-3604?
How do I fix CVE-2026-3604?
No fix has been published for CVE-2026-3604 yet. Limit exposure of the affected software until one is available.
Escape output for the context it lands in and set a strict Content Security Policy. Upgrading the affected component is the real fix. More about Cross-site scripting.
Is CVE-2026-3604 being exploited?
There is no known exploitation of CVE-2026-3604 in the wild and no public exploit code.
Sources
Also known as GHSA-vfvr-pxr9-rgwp.