All vulnerabilities
CVE-2026-103594

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

WatchGuard Fireware OSNetwork & edge
Open in ThreatlineRecord JSON
CVSS
9.5Critical
ExploitationNo known exploitationNot in CISA KEV, which does not prove it is unexploitedCISA KEV
Exploit odds (EPSS)No scoreNo FIRST EPSS score in this snapshot yet
Fixed in2026.4Also 12.12.4CVE List
Published27 Oct 2026Updated 27 Oct 2026CVE List

What fixes it

A fixed version on one release line is not the upgrade target for every line. Check your exact version and any vendor backports.

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.

Text from CVE List

Affected versions 2

  • Fireware OSaffected: 2026.2 before 2026.4CVE List
  • Fireware OSaffected: 12.12 before 12.12.4CVE List

References 1