CVE-2026-18145 PUBLISHED

Fireware OS Stack-based Buffer Overflow in spamd Allows Remote Code Execution

Assigner: WatchGuard
Reserved: 28.07.2026 Published: 29.09.2026 Updated: 30.09.2026

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.

Metrics

CVSS 4.0

CVSS Vector: 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
CVSS Score: 8.6

Exploitability Metrics		Vulnerable System Impact Metrics		Subsequent System Impact Metrics
Attack Vector	Network	Confidentiality	High	Confidentiality	None
Attack Complexity	Low	Integrity	High	Integrity	None
Attack Requirements	None	Availability	High	Availability	None
Privileges Required	High
User Interaction	None

CVSS 4.0

Product Status

Vendor	WatchGuard
Product	Fireware OS
Versions	Default: unaffected affected from 2026.3 to 2026.3.2 (excl.) affected from 2025.0 to 2026.2.3 (excl.) affected from 12.0 to 12.12.3 (excl.)

Vendor	WatchGuard
Product	Fireware OS
Versions	Default: unaffected affected from 12.0 to 12.5.21 (excl.)

Exploits

WatchGuard is not aware of any exploitation of this vulnerability in the wild.

Solutions

Fireware OS 2026.3.2, Fireware OS 2026.2.3, Fireware OS 12.12.3, Fireware OS 12.5.21

Credits

Nicholas Zubrisky (@NZubrisky) of TrendAI Research finder

References

https://psirt.watchguard.com/CVE-2026-18145

Problem Types

CWE-121 CWE