CVE-2026-81433 Fireware OS Pre-Authentication Stack Buffer Overflow in fingerd Allows Remote Code Execution
Unauthenticated attackers with adjacent network access can execute arbitrary code or crash the device via crafted DHCP packets in WatchGuard Fireware OS.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-81433?
CVE-2026-81433 is a high-severity memory corruption vulnerability in WatchGuard Fireware OS, published on 29 Sep 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
A stack-based buffer overflow vulnerability in WatchGuard Fireware OS's DHCP fingerprinting daemon (fingerd) allows an unauthenticated attacker with adjacent network access to execute arbitrary code or crash the process by sending a specially crafted DHCP packet.
Which versions are affected by CVE-2026-81433?
How do I fix CVE-2026-81433?
No fix has been published for CVE-2026-81433 yet. Limit exposure of the affected software until one is available.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is CVE-2026-81433 being exploited?
There is no known exploitation of CVE-2026-81433 in the wild and no public exploit code.
Sources
Also known as GHSA-h8f9-rp2r-962g.