CVE-2025-39430 Overview
CVE-2025-39430 is a Cross-Site Request Forgery (CSRF) vulnerability in the Alexander Rauscha mLanguage plugin for WordPress. The flaw affects all versions of mLanguage up to and including 1.6.1. Successful exploitation chains the CSRF weakness into a Stored Cross-Site Scripting (XSS) attack against the WordPress site. An attacker tricks an authenticated administrator into visiting a crafted page, which triggers an unauthorized request that persists malicious JavaScript on the site.
Critical Impact
Attackers can persist arbitrary JavaScript in the WordPress admin context by abusing missing CSRF protections, enabling session theft, admin account takeover, and visitor-side script execution.
Affected Products
- Alexander Rauscha mLanguage WordPress plugin
- mLanguage versions from initial release through 1.6.1
- WordPress sites with the vulnerable plugin installed and activated
Discovery Timeline
- 2025-04-17 - CVE-2025-39430 published to the National Vulnerability Database
- 2026-04-23 - Last updated in NVD database
Technical Details for CVE-2025-39430
Vulnerability Analysis
The vulnerability is classified under [CWE-352] Cross-Site Request Forgery. The mLanguage plugin exposes state-changing administrative endpoints without verifying request authenticity through anti-CSRF tokens (WordPress nonces). When an authenticated administrator visits an attacker-controlled page, the browser silently submits a forged request to the vulnerable plugin endpoint using the admin's existing session.
Because the affected endpoint also fails to sanitize or encode supplied input before storing it, the CSRF flaw escalates into Stored XSS. Injected JavaScript persists in plugin-managed content and executes in the browser of any user who renders the affected page. The attack requires user interaction (UI:R) but no privileges from the attacker, and impacts confidentiality, integrity, and availability at limited levels with a changed scope.
Root Cause
The root cause is the absence of CSRF token validation on administrative request handlers within the mLanguage plugin. WordPress provides wp_nonce_field() and check_admin_referer() primitives for this purpose, but the vulnerable code paths do not enforce them. Combined with insufficient output encoding on stored data, the missing token check converts a CSRF primitive into persistent script injection.
Attack Vector
Exploitation is network-based and requires an authenticated administrator to load an attacker-controlled URL or visit a page that loads a hostile resource. The attacker hosts an HTML page containing a hidden form or fetch request that targets the vulnerable mLanguage endpoint. When the admin's browser submits the request, the plugin processes it as legitimate and stores the attacker-supplied JavaScript payload. The payload then executes whenever the affected language configuration or content is rendered.
No verified public exploit code is available. See the Patchstack CSRF Vulnerability Report for additional technical context.
Detection Methods for CVE-2025-39430
Indicators of Compromise
- Unexpected <script> tags, onerror, onload, or javascript: URIs stored in mLanguage plugin database tables or options
- WordPress admin-side POST requests to mLanguage endpoints originating from external Referer headers
- New or modified administrator accounts created shortly after an admin browsing session
- Outbound requests from site visitors' browsers to unfamiliar domains after loading translated content
Detection Strategies
- Audit the WordPress wp_options table and plugin-specific tables for HTML or script content in fields expected to hold plain text.
- Inspect web server access logs for POST requests to mLanguage admin handlers that lack a same-origin Referer header.
- Review browser DOM and rendered HTML on public pages for injected script tags that did not originate from theme or plugin templates.
Monitoring Recommendations
- Enable a Web Application Firewall (WAF) with rules covering CSRF and stored XSS patterns targeting WordPress plugins.
- Monitor file integrity and database content for unauthorized changes to plugin-managed translation strings.
- Alert on administrator session activity originating from unusual geolocations or accompanied by cross-origin POST requests.
How to Mitigate CVE-2025-39430
Immediate Actions Required
- Deactivate the mLanguage plugin until a fixed version is installed, especially on sites with multiple administrators.
- Rotate WordPress administrator passwords and invalidate active sessions after confirming the plugin is contained.
- Scan the database and rendered pages for injected JavaScript and remove any malicious payloads.
Patch Information
At the time of publication, no vendor-supplied fixed version is referenced in the NVD entry. Versions through 1.6.1 are affected. Track the Patchstack CSRF Vulnerability Report for updates on a patched release.
Workarounds
- Restrict access to wp-admin by IP allowlist at the web server or WAF layer to reduce CSRF exposure.
- Require administrators to use isolated browser profiles or sessions when managing WordPress to limit cross-site request abuse.
- Deploy a WAF rule that blocks cross-origin POST requests to mLanguage admin endpoints lacking a valid _wpnonce parameter.
- Replace mLanguage with an actively maintained translation plugin if a vendor patch is not released in a timely manner.
# Example: temporarily disable the mLanguage plugin via WP-CLI
wp plugin deactivate mlanguage
wp plugin status mlanguage
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
