Critical vulnerabilities identified in WatchGuard Fireware OS
The German federal cybersecurity team CERT-Bund has warned of 18 vulnerabilities affecting WatchGuard appliances and VPN clients, including seven critical flaws.
Germany’s Computer Emergency Response Team (CERT-Bund) has issued a security alert regarding a series of vulnerabilities within WatchGuard’s Fireware OS and its corresponding Windows VPN client. Seven of the 18 identified flaws are classified as critical, carrying CVSS scores between 9.1 and 9.5. The agency has assigned the overall warning a maximum severity rating.
The vulnerabilities allow for remote code execution, often with root privileges, as well as denial-of-service attacks and the circumvention of security barriers. The security risks are contingent on specific device configurations, including those running Access Portals, SIP proxies, or operating in FIPS mode.
While WatchGuard states there is no evidence of active exploitation, the manufacturer has released patches to address the security holes. Customers are urged to update to Fireware OS 2026.4 or 12.12.4. Users of T15 and T35 models must update to 12.5.22, while the VPN client requires an update to version 2026.4.