Authenticated users with contributor-level permissions or higher can exploit this by sending a crafted JSON payload to the '/wp-json/sowb/v1/widgets/previews' REST endpoint. The payload must include a legacy top-level 'theme' key combined with a non-empty 'columns' array. This combination allows the attacker to bypass field validation because the 'update_fields()' function fails to strictly validate the provided data against declared form fields. By supplying a path to an existing .php file on the server, the attacker can force the application to include and execute the target file, leading to unauthorized code execution and potential privilege escalation or sensitive data access.

Impact

Successful exploitation allows authenticated attackers with minimal privileges (contributor) to achieve remote code execution on the WordPress server. This can lead to full site compromise, unauthorized database access, or lateral movement within the hosting environment.

Recommendation

• Update the SiteOrigin Widgets Bundle plugin to a version patched against CVE-2026-92174.
• Audit WordPress user permissions to identify and restrict accounts with 'contributor' status or higher that may be untrusted.
• Monitor access logs for unauthorized or suspicious POST requests to the '/wp-json/sowb/v1/widgets/previews' endpoint, specifically looking for JSON payloads containing 'theme' and 'columns' keys.