CVE-2026-12906 Overview
CVE-2026-12906 is a broken access control vulnerability in the RTMKit WordPress plugin before version 2.0.9. The plugin exposes an AJAX action that fails to perform a capability check and resolves a request-supplied post identifier directly. Authenticated users holding at least the Contributor role can read the titles of other users' private, draft, pending, scheduled, and trashed posts. The issue results from missing authorization on a low-privilege AJAX endpoint combined with an insecure direct object reference.
Critical Impact
Authenticated Contributor-level users can enumerate and disclose titles of non-public WordPress posts owned by other users, including drafts and scheduled content.
Affected Products
- RTMKit WordPress plugin versions prior to 2.0.9
Discovery Timeline
- 2026-07-16 - CVE-2026-12906 published to NVD
- 2026-07-16 - Last updated in NVD database
Technical Details for CVE-2026-12906
Vulnerability Analysis
The RTMKit plugin registers an AJAX action available to authenticated users. The handler accepts a post identifier from the client request and returns metadata for that post without verifying whether the caller has permission to view it. This pattern is a classic Insecure Direct Object Reference [CWE-639] combined with Missing Authorization [CWE-862].
WordPress exposes AJAX endpoints under admin-ajax.php. Handlers must call current_user_can() or an equivalent capability check before returning data tied to a specific object. The vulnerable RTMKit handler skips this step. As a result, any user with edit_posts or a comparable Contributor-level capability can supply arbitrary numeric post IDs.
The response leaks post titles for content that is otherwise restricted. This includes private posts, unpublished drafts, pending review items, scheduled future posts, and trashed content. While the disclosure is limited to titles rather than full body content, titles frequently contain sensitive product names, embargoed announcements, or internal project references.
Root Cause
The root cause is the absence of a per-object capability check inside the AJAX callback. The handler trusts the authenticated session context without validating that the session's user has rights to the specific post identified in the request. Post visibility rules enforced by get_post() and map_meta_cap() are bypassed because the plugin retrieves and echoes fields directly.
Attack Vector
An attacker first obtains a Contributor account through legitimate registration, compromised credentials, or social engineering. The attacker then issues authenticated POST requests to admin-ajax.php specifying the vulnerable RTMKit action and iterating post IDs sequentially. Each response reveals the title of the referenced post regardless of its status or owner. Enumeration across a numeric ID range yields a full inventory of non-public post titles on the site. Refer to the WPScan Vulnerability Report for additional technical detail.
Detection Methods for CVE-2026-12906
Indicators of Compromise
- Repeated authenticated POST requests to wp-admin/admin-ajax.php from a single Contributor account within a short window
- Sequential or wide-ranging post_id parameter values in AJAX requests targeting RTMKit actions
- Contributor accounts accessing AJAX endpoints outside their normal editorial workflow
Detection Strategies
- Parse web server access logs for high-volume admin-ajax.php traffic tied to non-administrative user sessions
- Alert on any account with contributor role generating more than a baseline number of AJAX calls per minute
- Correlate WordPress audit log entries with HTTP request logs to identify enumeration patterns
Monitoring Recommendations
- Enable a WordPress activity logging plugin to capture AJAX action names and user context
- Forward web server logs to a centralized log platform for retention and query
- Review Contributor account creation events and monitor newly registered accounts for anomalous behavior
How to Mitigate CVE-2026-12906
Immediate Actions Required
- Update the RTMKit WordPress plugin to version 2.0.9 or later on all affected sites
- Audit existing Contributor-level accounts and remove or downgrade unused accounts
- Review WordPress user registration settings and disable open registration if not required
Patch Information
Upgrade RTMKit to version 2.0.9 or newer. The fixed release adds the missing capability check to the affected AJAX handler and enforces post-level authorization before returning metadata. Consult the WPScan Vulnerability Report for advisory details.
Workarounds
- Deactivate the RTMKit plugin until the patched version can be deployed
- Restrict access to admin-ajax.php for Contributor-role users through a web application firewall rule targeting the vulnerable action name
- Temporarily remove the Contributor role from users who do not require immediate authoring access
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
