WatchGuard FireWare OS spamd statushdlr Stack-based Buffer Overflow Remote Code Execution Vulnerability

September 30th, 2026
ZDI-26-750 ZDI-CAN-31623

CVE ID

CVE-2026-18145

CVSS Score

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

Affected Vendors

WatchGuard

Affected Products

FireWare OS

Vulnerability Details

This vulnerability allows remote attackers to execute arbitrary code on affected installations of WatchGuard FireWare OS. Authentication is required to exploit this vulnerability.

The specific flaw exists within the handling of xpath and parameter values provided to the spamd daemon's status and action handlers. 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 the spamd process.

Additional Details

WatchGuard has issued an update to correct this vulnerability. More details can be found at:
https://psirt.watchguard.com/CVE-2026-18145

Disclosure Timeline

  • 2026-06-02 - Vulnerability reported to vendor
  • 2026-09-30 - Coordinated public release of advisory
  • 2026-09-30 - Advisory Updated

Credit

Nicholas Zubrisky (@NZubrisky) of TrendAI Research

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