WatchGuard FireWare OS epm connect Stack-based Buffer Overflow Remote Code Execution Vulnerability

September 9th, 2026
ZDI-26-632 ZDI-CAN-30460

CVE ID

CVE-2026-13086

CVSS Score

8.8 AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Affected Vendors

WatchGuard

Affected Products

FireWare OS

Vulnerability Details

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 specific flaw exists within the Endpoint Protection Manager service. The issue results from the lack of proper validation of the length of user-supplied data prior to copying it to a fixed-length stack-based buffer. An attacker can leverage this vulnerability to execute code in the context of root.

Additional Details

WatchGuard has issued an update to correct this vulnerability. More details can be found at:
https://psirt.watchguard.com/CVE-2026-13086

Disclosure Timeline

  • 2026-04-16 - Vulnerability reported to vendor
  • 2026-09-09 - Coordinated public release of advisory
  • 2026-09-09 - Advisory Updated

Credit

Mat Powell of TrendAI Zero Day Initiative

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