Vulnerability · Published Sep 29, 2026 · Assigned by WatchGuard
CVE-2026-18145Fireware OS Stack-based Buffer Overflow in spamd Allows Remote Code Execution
High 8.6
In plain English
A high-severity stack buffer overflow in Fireware OS from WatchGuard. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 33% of all known vulnerabilities).
Severity (CVSS 4.0)8.6High
Exploit odds (30 days)0.4%top 66.8% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known
Official 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.
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| WatchGuard | Fireware OS | 2026.3 – before 2026.3.22025.0 – before 2026.2.312.0 – before 12.12.3 |
| WatchGuard | Fireware OS | 12.0 – before 12.5.21 |
Weakness: CWE-121 · 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
References
- https://psirt.watchguard.com/CVE-2026-18145 vendor-advisory