CVE-2026-16098: critical vulnerability in ProSolution WP Client

The ProSolution WP Client plugin for WordPress is vulnerable to Arbitrary File Upload in all versions up to, and including, 2.0.10 via the proSol_handleFileUpload function. This is due to missing validation of the attacker-controlled Content-Disposition header filename, which overrides the allow-listed multipart filename before the file is saved, and a post-save extension check that fails to delete the already-written file. This makes it possible for unauthenticated attackers to upload files that may be executable, which makes remote code execution possible. The nonce required to reach the upload handler is publicly exposed via wp_localize_script on any front-end page rendering the job portal shortcode, allowing unauthenticated visitors to obtain a valid nonce and bypass that gating check entirely.