CVE-2026-16057 Overview
CVE-2026-16057 affects the Contest Gallery WordPress plugin in versions prior to 30.0.7. The plugin fails to perform per-object capability or nonce checks in one of its post-deletion handlers. The handler relies only on a coarse role-membership test, allowing any authenticated user with Author-level access or higher to permanently delete arbitrary posts, pages, and other content they do not own. The weakness maps to CWE-862 (Missing Authorization).
Critical Impact
Authenticated users with low-privilege Author roles can permanently delete arbitrary WordPress content site-wide, causing integrity and availability damage.
Affected Products
- Contest Gallery WordPress plugin versions before 30.0.7
- WordPress sites permitting Author-level or higher user registrations
- Multi-author WordPress installations using Contest Gallery for contest management
Discovery Timeline
- 2026-08-03 - CVE-2026-16057 published to NVD
- 2026-08-04 - Last updated in NVD database
Technical Details for CVE-2026-16057
Vulnerability Analysis
The Contest Gallery plugin exposes a post-deletion handler intended for content management within the plugin's workflow. The handler is reachable by authenticated users but does not validate whether the requesting user owns the target object. It also omits the nonce validation that WordPress requires for state-changing requests. As a result, any user session with the Author role or higher can invoke the handler and pass an arbitrary post identifier for deletion.
Because the deletion is executed against the WordPress database directly, it removes posts, pages, custom post types, and other content regardless of author. The action is not scoped to Contest Gallery entries. The attack requires authentication, which limits scope to sites that provision Author-level accounts, but the integrity and availability impact on affected content is complete.
Root Cause
The root cause is a missing authorization check (CWE-862). The handler substitutes a role-membership test for the required current_user_can('delete_post', $post_id) capability check and skips wp_verify_nonce() validation. Coarse role gating cannot enforce per-object ownership.
Attack Vector
An authenticated attacker holding an Author, Editor, or Contributor account with elevated privilege sends a crafted HTTP request to the vulnerable plugin endpoint. The request supplies the target post identifier. The handler executes the deletion without ownership or nonce validation. Refer to the WPScan Vulnerability Report for technical details.
Detection Methods for CVE-2026-16057
Indicators of Compromise
- Unexpected wp_posts deletions or post_status transitions to trash performed by non-owner Author accounts
- WordPress audit log entries showing bulk or targeted content deletion originating from low-privilege user sessions
- HTTP POST requests to Contest Gallery admin-ajax or plugin endpoints containing arbitrary post_id parameters
Detection Strategies
- Monitor WordPress activity logs for deleted_post hook invocations initiated by users who are not the post author
- Alert on Contest Gallery plugin endpoint requests that lack a valid _wpnonce parameter
- Correlate deletion events with the acting user's role and compare against object ownership metadata
Monitoring Recommendations
- Enable a WordPress audit logging plugin capturing user, action, target object, and source IP for every content deletion
- Forward web server access logs and WordPress logs to a centralized SIEM for anomaly detection on deletion volume per user
- Baseline normal Author-level activity and flag deviations involving cross-author content modification
How to Mitigate CVE-2026-16057
Immediate Actions Required
- Update the Contest Gallery plugin to version 30.0.7 or later on all WordPress installations
- Audit existing Author, Editor, and Contributor accounts and remove or downgrade unused elevated roles
- Restore any content deleted by unauthorized users from the most recent verified backup
Patch Information
The vendor addressed the vulnerability in Contest Gallery version 30.0.7. The fix introduces per-object capability checks and nonce validation in the affected deletion handler. Details are documented in the WPScan Vulnerability Report.
Workarounds
- Temporarily deactivate the Contest Gallery plugin until the patched version is installed
- Restrict Author-level and higher account provisioning to trusted users only
- Deploy a Web Application Firewall (WAF) rule blocking requests to the vulnerable plugin endpoint that lack a valid nonce
# Update Contest Gallery via WP-CLI
wp plugin update contest-gallery --version=30.0.7
wp plugin status contest-gallery
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
