CVE-2026-21718: Copeland Xweb 300d Pro Firmware

Critical severity, CVSS 9.8. EPSS: 0.4% chance of exploitation in the next 30 days.

An authentication bypass vulnerability exists in Copeland XWEB Pro version 1.12.1 and prior, enabling any attackers to bypass the authentication requirement and achieve pre-authenticated code execution on the system.

Affected products

• Copeland Xweb 300d Pro Firmware: up to and including 1.12.1
• Copeland Xweb 500b Pro Firmware: up to and including 1.12.1
• Copeland Xweb 500d Pro Firmware: up to and including 1.12.1

Published 2026-02-27. Last modified 2026-06-17.