CVE-2025-7431 Overview
CVE-2025-7431 is a Stored Cross-Site Scripting (XSS) vulnerability in the Knowledge Base plugin for WordPress. The flaw affects all versions up to and including 2.3.1. It stems from insufficient input sanitization and output escaping on the plugin slug setting. Authenticated attackers with administrator-level access can inject arbitrary web scripts into pages. These scripts execute in the browser of any user who accesses an affected page. The vulnerability only impacts multi-site installations or single-site installations where the unfiltered_html capability has been disabled. It is classified under CWE-79.
Critical Impact
Authenticated administrators on multi-site WordPress deployments can persist JavaScript payloads that execute for any visitor rendering the injected page.
Affected Products
- WordPress Knowledge Base plugin versions up to and including 2.3.1
- WordPress multi-site installations running the vulnerable plugin
- Single-site WordPress installations with unfiltered_html capability disabled
Discovery Timeline
- 2025-07-18 - CVE-2025-7431 published to the National Vulnerability Database
- 2026-06-17 - Last updated in NVD database
Technical Details for CVE-2025-7431
Vulnerability Analysis
The vulnerability resides in the plugin's settings handler for the plugin slug configuration. The Knowledge Base plugin accepts administrator-supplied input for its slug value but fails to properly sanitize the input on save and fails to escape it on output. When the stored slug value is later rendered on a page, injected HTML or JavaScript executes in the visitor's browser context.
Stored XSS in a slug field is persistent. Every page that renders the affected setting delivers the payload to end users. Because the payload originates from a trusted admin control, output routines assumed the value was safe and skipped contextual encoding. The relevant code path can be reviewed in the WordPress Settings Class Code and additional analysis is available from the Wordfence Vulnerability Analysis.
Root Cause
The root cause is missing input sanitization when persisting the plugin slug setting, combined with missing output escaping when the value is rendered. WordPress provides helpers such as sanitize_text_field() on save and esc_html() or esc_attr() on output. Neither pattern is enforced in the vulnerable code path, allowing raw markup to survive round-trip storage.
Attack Vector
Exploitation requires an authenticated attacker with administrator-level access. The attacker navigates to the plugin's settings page and stores a JavaScript payload in the slug field. The precondition is a multi-site installation or an installation where site administrators have had the unfiltered_html capability revoked. Under those configurations, WordPress normally filters administrator input, so this class of stored XSS becomes a meaningful privilege boundary. When any user subsequently visits a page that outputs the slug, the payload executes in that user's session.
No verified public proof-of-concept code is available for this issue. See the referenced advisories for technical detail.
Detection Methods for CVE-2025-7431
Indicators of Compromise
- Presence of HTML tags, <script> markers, or JavaScript event handlers stored in the Knowledge Base plugin slug option within the WordPress wp_options table.
- Unexpected outbound network requests from visitor browsers when loading Knowledge Base pages.
- Modification of Knowledge Base plugin settings by administrator accounts that do not normally configure the plugin.
Detection Strategies
- Audit the stored slug value in the plugin's options and validate that it contains only URL-safe characters.
- Review WordPress audit logs for administrator changes to Knowledge Base plugin settings.
- Scan rendered Knowledge Base pages for unexpected inline script content or third-party script references.
Monitoring Recommendations
- Enable a WordPress activity logging plugin to record administrator setting changes with user attribution.
- Deploy a Content Security Policy (CSP) with reporting to surface script execution violations from injected payloads.
- Monitor web server access logs for anomalous request patterns tied to Knowledge Base URLs following administrator setting changes.
How to Mitigate CVE-2025-7431
Immediate Actions Required
- Update the WordPress Knowledge Base plugin to a version later than 2.3.1 as soon as a fixed release is available from the vendor.
- Review current values stored for the plugin slug setting and remove any HTML or script content.
- Restrict administrator accounts on multi-site installations to trusted operators and enforce multi-factor authentication.
Patch Information
At the time of publication, review the plugin's WordPress.org listing and the Wordfence Vulnerability Analysis for the current fixed version. Apply the vendor-provided update through the WordPress plugin management interface or wp-cli.
Workarounds
- Deactivate the Knowledge Base plugin on multi-site installations until a patched version is installed.
- Enforce a strict Content Security Policy that disallows inline scripts on pages rendered by the plugin.
- Limit which administrator accounts can modify plugin settings by using role management to reduce the attack surface.
# Update the plugin via wp-cli once a fixed release is published
wp plugin update knowledgebase
# Verify the installed version
wp plugin get knowledgebase --field=version
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
