by Kastro
Paper/Archive/CVE-2026-103594

CVE-2026-103594

WatchGuard Fireware OS — Fireware OS Stack Buffer Overflow in WireGuard Configuration Allows Remote Code Execution

EPSS 0.4%CVSS 9.5
critical.is priorityof 100
36
CVSS 9.5 (CNA)9.5 / 10 × 3028.5Not in CISA KEV+300.0EPSS percentile 37.5.375 × 207.5No public exploit+100.0SSVC exploitation: unknown+100.0
Description · from the CVE record

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.

Affected

ProductAffectedFixed inSource
Fireware OS2026.2 – < 2026.42026.4CNA
Fireware OS12.12 – < 12.12.412.12.4CNA

Scores by source

WatchGuard (CNA)9.5CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H

References

advisorypsirt.watchguard.com/CVE-2026-103594