---
id: CVE-2026-18145
title: >-
  A stack-based buffer overflow vulnerability in the spamBlocker (spamd) service
  of WatchGuard Fireware OS allows an authenticated attacker with administrator
  privileges to crash the service or potentially execute arbitrary code by
  sending…
summary: >-
  A stack-based buffer overflow vulnerability in the spamBlocker (spamd) service
  of WatchGuard Fireware OS allows an authenticated attacker with administrator
  privileges to crash the service or potentially execute arbitrary code by
  sending…
severity: high
cvss: 8.6
cvssVector: 'CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N'
cwe:
  - CWE-121
vendor: WatchGuard
product: Fireware OS
affected:
  - fireware_os >= 2026.3 < 2026.3.2
  - fireware_os >= 2025.0 < 2026.2.3
  - fireware_os >= 12.0 < 12.12.3
  - fireware_os >= 12.0 < 12.5.21
published: '2026-09-30'
updated: '2026-09-30'
sourceUpdated: '2026-09-30T00:16:36.003'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-18145'
references:
  - url: 'https://psirt.watchguard.com/CVE-2026-18145'
    label: 5d1c2695-1a31-4499-88ae-e847036fd7e3
tags:
  - nvd
  - cve.org
cvssSource: cna
ingestedAt: '2026-09-29T23:52:50.548Z'
---

## Overview

A stack-based buffer overflow vulnerability in the spamBlocker (spamd) service of WatchGuard Fireware OS allows an authenticated attacker with administrator privileges to crash the service or potentially execute arbitrary code by sending a specially crafted management request.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.