XSS in Comesio Relevanssi – A Better Search

CVE-2026-19985

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.

Vulnerability class: XSS (Cross-Site Scripting)

Published · last modified .

CVSS v3 metric

CVSS v3 base score 6.1 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N.

EPSS exploit prediction

EPSS: 0.005 (39.7th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 40th percentile — 39.7% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-19985: held from 0.003 to 0.005.

EPSS over last 30 days · oldest: 0.003 · newest: 0.005 · change: +0.002

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-19985?
CVE-2026-19985 is a medium-severity vulnerability in Comesio Relevanssi – A Better Search, classified under Cross-site Scripting. CVSS score: 6.1/10. Published 2026-09-11.
How severe is CVE-2026-19985?
Medium severity. CVSS v3 base score is 6.1 out of 10.