ZDI 2026-09-30

ZDI-26-749: WatchGuard FireWare OS samld SAMLSession Deserialization of Untrusted Data Remote Code Execution Vulnerability

CVE-2026-13046

Machine-generated analysis · WAYSCloud LLM

Exploitation requires write access to the samld session directory.

Context

The advisory concerns the samld component of WatchGuard FireWare OS. It describes a deserialization of untrusted data that can lead to remote code execution. The attacker must first obtain the ability to write to the samld session directory.

Operator considerations

Check: Verify that the samld session directory is not writable by unauthorized users.
Isolate: Restrict or isolate the samld service to limit write access to its session directory.
Log: Enable logging of file creation or modification events in the samld session directory.

From Zero Day Initiative ↗

This vulnerability allows remote attackers to execute arbitrary code on affected installations of WatchGuard FireWare OS. An attacker must first obtain the ability to write to the samld session directory on the target system in order to exploit this vulnerability. The ZDI has assigned a CVSS rating of 7.5. The following CVEs are assigned: CVE-2026-13046.

Read the full advisory on ZDI →

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