Critical severity · published Oct 27, 2026
CVE-2026-103594
Fireware OS Stack Buffer Overflow in WireGuard Configuration Allows Remote Code Execution
New
9.5
CVSS
–
EPSS
No
On KEV
Description
A stack-based buffer overflow vulnerability in Fireware OS's WireGuard configuration processing allows a remote attacker that has man-in-the-middle TLS-decrypted access between the Firebox and WatchGuard Cloud to create a Denial of Service condition and potentially execute arbitrary code by tampering with a FireCloud Gateway configuration payload.
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
2026.2 before 2026.4; 12.12 before 12.12.4 · source: vendor
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-103594
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-103594
psirt.watchguard.com
https://psirt.watchguard.com/CVE-2026-103594
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