WatchGuard discloses seven critical Fireware OS flaws enabling remote code execution
Supplied data names Fireware OS 2026.4 and 12.12.4 as fixes; this report does not establish exploitation.
74
CVE-2026-103594
Stack buffer overflow in Fireware OS WireGuard config via MITM
- CVSS 4.0
- 9.5 critical
- EPSS
- —
- Published
- ·
- Modified
AI analysisSummaries by Vani AI
A stack-based buffer overflow in Fireware OS occurs while processing WireGuard configuration. A remote attacker who already has man-in-the-middle access with TLS decryption between a Firebox and WatchGuard Cloud can tamper with a FireCloud Gateway configuration payload. That can cause denial of service and may allow arbitrary code execution. Fireboxes using Fireware OS with that cloud configuration path are affected.
What to do: Apply WatchGuard's update for CVE-2026-103594 when it is available. No workaround is stated.
| Product | Affected |
|---|---|
| WatchGuard Fireware OS | — |
Estimated exposure
nicheNo basis for an estimate.
Order-of-magnitude estimate by the model from install counts, market share and public scan data it knows; verify before quoting.
Description · NVD
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.
- Weakness
- CWE-121, CWE-787, CWE-1284
- 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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X