Relevanssi <= 4.28.1 — Reflected Cross-Site Scripting

Am I affected?

• Check your version: in wp-admin go to Plugins → Installed Plugins and read the version under Relevanssi – A Better Search.
• No admin access? Run a passive check of your site. It reads public files only.
• No account is needed to exploit this. Treat any exposed site on an affected version as at risk.

What to do

1. Update to version 4.28.2, or a newer patched version
2. Rotate administrator passwords and application secrets if the site ran a vulnerable version while publicly reachable.
3. Watch Relevanssi – A Better Search to get an email when the next vulnerability is published.

Advisory

Source description from Wordfence Intelligence, credited to Mutantgun.

The Relevanssi – A Better Search plugin for WordPress is vulnerable to Reflected Cross-Site Scripting in versions up to, and including, 4.28.1 via the 's', 'post_types', and 'orderby' request parameters. This is due to insufficient input sanitization and output escaping in the relevanssi_debug_array() function in lib/debug.php, which dumps user-supplied query variables through print_r() inside a <pre> block without HTML escaping. The debug path is enabled by supplying the relevanssi_debug=on request parameter when the administrator has previously enabled the 'Debugging mode' setting; the gate itself is a configuration check with no capability, nonce, or logged-in check (the vendor explicitly suppresses nonce verification on that line). This makes it possible for unauthenticated attackers to inject arbitrary web scripts in pages that execute if they can successfully trick a user into performing an action such as clicking on a specially crafted link.

Exploits & references

Proof-of-concept & detection

No public proof-of-concept or detection template is known for this vulnerability.

Advisories & patches

• Advisorywordfence.com

Related CVEs

Timeline

1. Sep 10, 2026

   CVE published

   Severity medium, CVSS 6.1

2. Nov 13, 2026

   Record last updated