A path traversal flaw in the Fireware OS Web UI can be leveraged by an authenticated user with privileged permissions to overwrite arbitrary files on the device. This vulnerability enables the execution of code within the context of an elevated system process, providing the attacker with full control of the firewall. The CVE description explicitly states the potential for arbitrary code execution, while the broader impacts on confidentiality, integrity, and availability are inferred based on the nature of the code execution flaw.

WatchGuard Fireware OS installations on Firebox devices, including all releases from version 12.6.1 through 12.11.8 and from 2025.1 through 2026.1.2.

The CVSS base score of 8.6 indicates a high severity vulnerability. Exploit probability data from EPSS is not available, and the vulnerability is not listed in the CISA KEV catalog. The flaw requires remote access to the Web UI and valid credentials with elevated privileges; thus, the attack vector is remote authenticated. Once an attacker authenticates, they can exploit the path traversal to place malicious files that the system process will execute.