CVE-2026-16966 Overview
CVE-2026-16966 is an information disclosure vulnerability in the Solace Extra WordPress plugin versions prior to 1.7.0. The plugin exposes an AJAX action that fails to perform authorization or post-status validation. Unauthenticated remote attackers can retrieve the contents of Site Builder parts in draft, pending, private, or trashed states. WordPress would normally restrict access to this non-published content. The flaw is classified under [CWE-200] (Exposure of Sensitive Information to an Unauthorized Actor). Confidentiality of unpublished editorial content, internal drafts, and private site configurations is at risk.
Critical Impact
Unauthenticated attackers can read draft, pending, private, and trashed Site Builder content that is not intended for public disclosure.
Affected Products
- Solace Extra WordPress plugin versions before 1.7.0
- WordPress sites using Solace Extra Site Builder functionality
- Any deployment relying on the vulnerable AJAX action for content management
Discovery Timeline
- 2026-09-02 - CVE-2026-16966 published to NVD
- 2026-09-02 - Last updated in NVD database
Technical Details for CVE-2026-16966
Vulnerability Analysis
The Solace Extra plugin registers an AJAX action intended to load Site Builder parts. The handler does not verify the requesting user's capabilities and does not check the post status before returning content. WordPress typically restricts non-published posts to authenticated users with appropriate roles. This handler bypasses those controls entirely. Any visitor can invoke the endpoint and retrieve content that authors have not yet released. The flaw falls under Broken Access Control and Information Disclosure categories.
Root Cause
The root cause is a missing authorization check combined with an absent post-status filter in the AJAX callback. WordPress plugins must validate user capabilities using functions such as current_user_can() and confirm post status before returning restricted objects. The vulnerable handler skips both steps. It queries and returns Site Builder parts regardless of whether the post is draft, pending, private, or trash. This design deviates from WordPress core access control expectations.
Attack Vector
Exploitation requires only network access to the target WordPress site. The attacker sends an unauthenticated HTTP request to wp-admin/admin-ajax.php specifying the vulnerable action and a target part identifier. The server returns the raw content of the requested Site Builder part. No user interaction, credentials, or privileges are required. Attackers can enumerate identifiers to harvest all non-published parts.
See the WPScan Vulnerability Report for technical details on the vulnerable AJAX action.
Detection Methods for CVE-2026-16966
Indicators of Compromise
- Unauthenticated POST or GET requests to /wp-admin/admin-ajax.php referencing the Solace Extra Site Builder AJAX action
- Repeated sequential requests enumerating numeric part identifiers from a single source IP
- Anomalous outbound response sizes from admin-ajax.php to unauthenticated sessions
Detection Strategies
- Inspect web server access logs for unauthenticated requests targeting the Solace Extra AJAX action parameter
- Alert on high-volume admin-ajax.php traffic where the action parameter matches Solace Extra endpoints and no authentication cookie is present
- Correlate WordPress audit logs with successful content retrieval events tied to non-published post statuses
Monitoring Recommendations
- Deploy a Web Application Firewall (WAF) rule to log and inspect requests to Solace Extra AJAX handlers
- Enable WordPress activity logging plugins to record access to draft and private content
- Monitor for scanning tools such as WPScan targeting the site's plugin directory
How to Mitigate CVE-2026-16966
Immediate Actions Required
- Update the Solace Extra WordPress plugin to version 1.7.0 or later immediately
- Audit existing draft, pending, private, and trashed Site Builder parts for sensitive information exposure
- Rotate any credentials, API keys, or internal URLs that may have been stored in unpublished content
Patch Information
The vendor addressed CVE-2026-16966 in Solace Extra version 1.7.0. The fix introduces authorization and post-status validation in the affected AJAX action. Site administrators should upgrade through the WordPress plugin dashboard or by replacing the plugin files with the patched release. Consult the WPScan Vulnerability Report for advisory details.
Workarounds
- Disable the Solace Extra plugin until the patched version can be deployed
- Block unauthenticated access to admin-ajax.php for the affected action at the WAF or reverse proxy layer
- Restrict access to the WordPress admin directory using IP allowlisting where feasible
# Update Solace Extra plugin via WP-CLI
wp plugin update solace-extra --version=1.7.0
wp plugin list --name=solace-extra --fields=name,status,version
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
