High severity · published Oct 27, 2026
CVE-2026-103593
Fireware OS Stack Buffer Overflow in Logging Service Allows Remote Code Execution
New
7.1
CVSS
–
EPSS
No
On KEV
Description
A stack-based buffer overflow vulnerability in the Fireware OS logging service allows a network-adjacent attacker who can impersonate or intercept traffic to the configured log server to execute arbitrary code with root privileges by presenting a specially crafted certificate.
Exploitation
Is it being used?
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
FO
Fireware OS · WatchGuard
2025.1 before 2026.4; 12.0 before 12.12.4; 12.0 before 12.5.22 · source: vendor
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-103593
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-103593
psirt.watchguard.com
https://psirt.watchguard.com/CVE-2026-103593
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