CVE-2026-18145

High

Description

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.

SeverityHigh

CVSS7.2

Exploit probability—

ProductWatchguard Fireware

PublishedSep 30, 2026

First seenSep 30, 2026

Weakness typeCWE-121CWE-121

How to fix

Update

watchguard fireware12.5.21, 12.12.3, 2026.2.3, 2026.3.2 or later

Vendor advisories

psirt.watchguard.com/CVE-2026-18145

Affected products

Product	Affected versions	Fixed in
watchguard fireware	12.0 ≤ v < 12.5.21, 12.12 ≤ v < 12.12.3, 2025.2 ≤ v < 2026.2.3, 2026.3 ≤ v < 2026.3.2	12.5.21, 12.12.3, 2026.2.3, 2026.3.2

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