Firebox and Fireware OS
CVE-2026-18145: Fireware OS Stack-based Buffer Overflow in spamd Allows Remote Code Execution
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.
Published
Automatic summary from the vendor's CVE record. We haven't written a full analysis of this vulnerability yet.
Affected and fixed versions
| Product / branch | Fixed in |
|---|---|
| Fireware OS (Default) 2026.3 | 2026.3.2 or later |
| Fireware OS (Default) 2025.0 | 2026.2.3 or later |
| Fireware OS (Default) 12.0 | 12.12.3 or later |
| Fireware OS (T15/T35) 12.0 | 12.5.21 or later |
Always confirm against the vendor advisory, which lists every fixed hotfix.
What it is
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.
Exploitation
WatchGuard is not aware of any exploitation of this vulnerability in the wild.
Sources
KEV status, EPSS score and vendor data refreshed automatically, last on 13 Oct 2026.