CVE-2026-19052: ProSolution WP Client Auth Bypass Flaw

CVE-2026-19052 Overview

CVE-2026-19052 affects the ProSolution WP Client WordPress plugin before version 2.0.9. The plugin fails to perform capability checks on two administrative AJAX actions. The nonce required by those actions is exposed on the public frontend of the site. Any authenticated user, including a low-privileged subscriber, can trigger an administrative data synchronisation and clear the plugin's activity records. The issue is tracked under CWE-862: Missing Authorization.

Critical Impact
Authenticated subscribers can invoke administrative AJAX handlers to force data synchronisation and wipe activity logs, undermining audit integrity.

Affected Products

ProSolution WP Client WordPress plugin versions prior to 2.0.9

Discovery Timeline

2026-08-12 - CVE-2026-19052 published to NVD
2026-08-12 - Last updated in NVD database

Technical Details for CVE-2026-19052

Vulnerability Analysis

The ProSolution WP Client plugin registers two AJAX actions intended for administrator use. Neither handler calls current_user_can() or an equivalent capability check before executing its logic. The plugin relies solely on a WordPress nonce for request validation. That nonce is rendered into markup on the plugin's public frontend, so any visitor authenticated at subscriber level or higher can read it.

Once armed with the nonce, an authenticated attacker can call the vulnerable endpoints from any browser session. The first action forces a synchronisation routine that pulls or pushes administrative data. The second action truncates the plugin's activity records, destroying the forensic trail of prior administrative actions.

Root Cause

The root cause is broken access control. The plugin conflates nonce verification with authorization, treating a valid nonce as sufficient proof of privilege. Because the nonce is emitted in a public context, the check degrades to a session-existence test rather than a role check.

Attack Vector

Exploitation requires network access to the target WordPress site and any authenticated account. The attacker loads a page that surfaces the AJAX nonce, then issues POST requests to admin-ajax.php invoking the affected actions. No user interaction from an administrator is needed. Impact is limited to data integrity: attackers can trigger synchronisation activity and erase the plugin's activity log without disclosing sensitive data or halting availability.

See the WPScan Vulnerability Report for additional technical detail.

Detection Methods for CVE-2026-19052

Indicators of Compromise

Unexpected POST requests to /wp-admin/admin-ajax.php originating from subscriber-level accounts targeting ProSolution WP Client action names.
Missing or truncated activity log entries within the ProSolution WP Client plugin data tables.
Unscheduled data synchronisation events initiated by non-administrator user IDs.

Detection Strategies

Correlate WordPress access logs with the plugin's audit trail to identify AJAX invocations by users lacking the manage_options capability.
Alert on any AJAX action associated with the plugin when the requesting user's role is subscriber, contributor, or author.
Monitor for gaps in sequential activity log identifiers, which can indicate log clearing.

Monitoring Recommendations

Ingest WordPress and web server logs into a centralized analytics platform to enable role-aware query rules for admin-ajax.php traffic.
Track new user registrations on sites where open registration is enabled, because subscriber accounts are the pivot for this attack.
Baseline normal synchronisation frequency for the plugin and alert on deviations.

How to Mitigate CVE-2026-19052

Immediate Actions Required

Upgrade the ProSolution WP Client plugin to version 2.0.9 or later on all WordPress installations.
Audit existing subscriber and low-privilege accounts and remove any that are unnecessary or unrecognized.
Review the plugin's activity records for gaps that may indicate prior exploitation.

Patch Information

The vendor addressed the issue in ProSolution WP Client version 2.0.9 by adding capability checks to the vulnerable AJAX handlers. Administrators should apply the update through the WordPress plugin dashboard or via WP-CLI. Refer to the WPScan Vulnerability Report for confirmation of the fixed version.

Workarounds

Disable the ProSolution WP Client plugin until the update to 2.0.9 can be applied.
Temporarily disable open user registration to prevent unauthenticated attackers from obtaining subscriber credentials.
Restrict access to admin-ajax.php for low-privilege roles at the web server or WAF layer where feasible.

bash

# Update the plugin using WP-CLI
wp plugin update prosolution-wp-client --version=2.0.9

# Verify installed version
wp plugin get prosolution-wp-client --field=version