CVE-2021-47936: Opencats

Critical severity, CVSS 9.8. EPSS: 0.7% chance of exploitation in the next 30 days.

OpenCATS 0.9.4 contains a remote code execution vulnerability that allows unauthenticated attackers to execute arbitrary commands by uploading malicious PHP files disguised as resume attachments. Attackers can upload PHP payloads through the careers job application endpoint and execute system commands via POST requests to the uploaded file in the upload directory.

Affected products

• Opencats Opencats: up to and including 0.9.4

Published 2026-05-10. Last modified 2026-10-06.