CVE-2026-103594 PUBLISHED

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

Assigner: WatchGuard
Reserved: 30.09.2026 Published: 27.10.2026 Updated: 27.10.2026

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.

Metrics

CVSS 4.0

CVSS Vector: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H
CVSS Score: 9.5

Exploitability Metrics		Vulnerable System Impact Metrics		Subsequent System Impact Metrics
Attack Vector	Network	Confidentiality	High	Confidentiality	High
Attack Complexity	Low	Integrity	High	Integrity	High
Attack Requirements	Present	Availability	High	Availability	High
Privileges Required	None
User Interaction	None

CVSS 4.0

Product Status

Vendor	WatchGuard
Product	Fireware OS
Versions	Default: unaffected affected from 2026.2 to 2026.4 (excl.) affected from 12.12 to 12.12.4 (excl.)

Affected Configurations

This vulnerability affects Firebox deployments configured to act as a FireCloud Gateway.

Exploits

WatchGuard is not aware of any exploitation of this vulnerability in the wild.

Solutions

Fireware OS 2026.4, Fireware OS 12.12.4

Credits

WatchGuard AI Security Research finder

References

https://psirt.watchguard.com/CVE-2026-103594

Problem Types

CWE-121 CWE
CWE-1284 CWE
CWE-787 CWE