High severity · published Sep 29, 2026
CVE-2026-18145
Fireware OS Stack-based Buffer Overflow in spamd Allows Remote Code Execution
7.2
CVSS
0.4%
EPSS
No
On KEV
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.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H
Attack vector
Network
Complexity
Low
Privileges
High
User interaction
None
Confidentiality
High
Integrity
High
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.4% · higher than 33% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
FO
Fireware OS · WatchGuard
2026.3 before 2026.3.2; 2025.0 before 2026.2.3; 12.0 before 12.12.3; 12.0 before 12.5.21 · source: vendor
FI
Fireware · Watchguard
12.0 before 12.5.21; 12.12 before 12.12.3; 2025.2 before 2026.2.3; 2026.3 before 2026.3.2 · source: NVD
In the news
VulnerabilityHigh
ZDI-26-750: WatchGuard FireWare OS spamd statushdlr Stack-based Buffer Overflow Remote Code Execution Vulnerability
This vulnerability allows remote attackers to execute arbitrary code on affected installations of WatchGuard FireWare OS. Authentication is required to exploit this vulnerability. The ZDI has assigned a CVSS rating of 7.2. The following CVEs are assigned: CVE-2026-18145.
Sep 30, 2026·Zero Day Initiative
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-18145
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-18145
vendor-advisory
https://psirt.watchguard.com/CVE-2026-18145
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