A deserialization of untrusted data vulnerability in WatchGuard Fireware OS's SAML single sign-on session handling (samld) allows an attacker who has already obtained the ability to write files on the appliance to execute arbitrary code in the context of the samld service by causing samld to load a maliciously crafted session file.
To exploit this vulnerability, an attacker requires network access to an authentication interface on the Firebox, such as the Access Portal. The attacker also needs to have obtained the ability to write arbitrary files to the filesystem.
WatchGuard is not aware of any exploitation of this vulnerability in the wild.
Fireware OS 2026.2.3, Fireware OS 12.12.3, Fireware OS 12.11.10