Vulnerability in WatchGuard Fireware OS

[ Why it matters ]Priority signals

• Critical severity: CVSS 9.5

[ Description ]Official 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.

[ Fixes ]Fixes and patches

No fix or interim patch is linked from our sources yet. Check the vendor references below and limit exposure of affected systems until a fix is available.

[ Advisories ]Government CERT advisories

• BSI CERT-Bund27 Oct 2026WID-SEC-2026-4209

  WatchGuard Fireware OS: Multiple vulnerabilities Translated from German

  CVE-2026-113881CVE-2026-103593CVE-2026-93434+15 more CVEs

[ References ]References

• psirt.watchguard.com/CVE-2026-103594