ZDI-26-428: WatchGuard FireWare OS admd Stack-based Buffer Overflow Remote Code Execution Vulnerability

Published Jul 15, 2026

Updated

This vulnerability allows network-adjacent attackers to execute arbitrary code on affected installations of WatchGuard FireWare OS. Authentication is not required to exploit this vulnerability. The ZDI has assigned a CVSS rating of 7.5. The following CVEs are assigned: CVE-2026-8247.

Affected Software

1 affected component

WatchGuard Fireware OS

Event History

Jul 15, 2026

Advisory Published

via ZDI·05:00 AM

Data Sourced

via ZDI·05:00 AM

Description

Frequently Asked Questions

What is the severity of ZDI-26-428?

The severity of ZDI-26-428 is rated at 7.5 on the CVSS scale.

How do I fix ZDI-26-428?

To fix ZDI-26-428, update your WatchGuard FireWare OS to the latest version that addresses this vulnerability.

What type of vulnerability is ZDI-26-428?

ZDI-26-428 is a stack-based buffer overflow vulnerability that allows remote code execution.

Who is affected by ZDI-26-428?

Network-adjacent attackers can exploit ZDI-26-428 on affected installations of WatchGuard FireWare OS.

Is authentication required to exploit ZDI-26-428?

No, authentication is not required to exploit the ZDI-26-428 vulnerability.

ZDI-26-428: WatchGuard FireWare OS admd Stack-based Buffer Overflow Remote Code Execution Vulnerability

Affected Software

Event History

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Frequently Asked Questions

What is the severity of ZDI-26-428?

How do I fix ZDI-26-428?

What type of vulnerability is ZDI-26-428?

Who is affected by ZDI-26-428?

Is authentication required to exploit ZDI-26-428?

Company

Resources

Contact

Frequently Asked Questions

What is the severity of ZDI-26-428?

How do I fix ZDI-26-428?

What type of vulnerability is ZDI-26-428?

Who is affected by ZDI-26-428?

Is authentication required to exploit ZDI-26-428?