CVE-2026-103426
Received Received - Intake

Stored XSS in Relevanssi Premium WordPress Plugin

Publication date: 2026-10-02

Last updated on: 2026-10-02

Assigner: Wordfence

Description
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.

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Meta Information

Published
2026-10-02
Last Modified
2026-10-02
Generated
2026-10-02
AI Q&A
2026-10-02
EPSS Evaluated
N/A
NVD
CVE-2026-103426
EUVD
EUVD-2026-91249

Affected Vendors & Products

Showing 1 associated CPE
Vendor Product Version / Range
relevanssi premium to 2.31.4 (inc)

Helpful Resources

Exploitability

CWE
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KEV
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CWE ID Description
CWE-79 The product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users.

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Executive Summary

This vulnerability is a Stored Cross-Site Scripting (XSS) flaw in the Relevanssi Premium WordPress plugin up to version 2.31.4. It allows unauthenticated attackers to inject malicious scripts via the '_rt' parameter due to insufficient input sanitization and output escaping. The scripts execute when users access infected pages, requiring the click-tracking feature to be enabled.

Detection Guidance

To detect this vulnerability, check if the Relevanssi Premium plugin is installed and active on your WordPress site. Inspect the plugin settings for the click-tracking and logging feature. Look for suspicious scripts in pages generated by the plugin, particularly those containing the '_rt' parameter. No specific commands are provided in the context.

Impact Analysis

Attackers could steal user sessions, redirect to malicious sites, or deface your website. Since it requires minimal prerequisites (enabled click-tracking and public _rt_nonce), the risk is high for any site using vulnerable versions.

Compliance Impact

This XSS flaw could lead to unauthorized data access or modification, violating GDPR (data protection) and HIPAA (health data security) by exposing sensitive user information. Compliance failures may result in legal penalties or reputational damage.

Mitigation Strategies

Immediately update the Relevanssi Premium plugin to the latest version beyond 2.31.4. Disable the click-tracking and logging feature if enabled. Review all pages for injected scripts and remove any unauthorized code. Monitor for unusual activity or unauthorized access.

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