What is CVE-2026-103426?

CVE-2026-103426 is a high-severity vulnerability in Relevanssi Premium, classified under Cross-site Scripting. CVSS score: 7.2/10. Published 2026-10-02.

How severe is CVE-2026-103426?

High severity. CVSS v3 base score is 7.2 out of 10.

XSS in Relevanssi Premium

CVE-2026-103426

The Relevanssi Premium plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the '_rt' parameter in all versions up to, and including, 2.31.4 due to insufficient input sanitization and output escaping. This makes it possible for unauthenticated attackers to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page. This requires the click-tracking and logging feature to be activated in the plugin settings, and exploitation is trivially accessible to unauthenticated users because a valid _rt_nonce is publicly emitted on every search-results page.

Vulnerability class: XSS (Cross-Site Scripting)

Published 2026-10-02 · last modified 2026-10-02.

CVSS v3 metric

CVSS v3 base score 7.2 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N.

EPSS exploit prediction

No EPSS score from FIRST.org yet. New CVEs usually get one within a few days; no score means no signal yet, not low risk. How EPSS works.

Affected products

Relevanssi Premium

Weakness classification (CWE)

CWE-79 — Cross-site Scripting

References

Frequently asked questions

What is CVE-2026-103426?: CVE-2026-103426 is a high-severity vulnerability in Relevanssi Premium, classified under Cross-site Scripting. CVSS score: 7.2/10. Published 2026-10-02.
How severe is CVE-2026-103426?: High severity. CVSS v3 base score is 7.2 out of 10.