CVE-2026-81433 PUBLISHED

Fireware OS Pre-Authentication Stack Buffer Overflow in fingerd Allows Remote Code Execution

Assigner: WatchGuard
Reserved: 26.08.2026 Published: 29.09.2026 Updated: 30.09.2026

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.

Metrics

CVSS 4.0

CVSS Vector: CVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
CVSS Score: 8.7

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

CVSS 4.0

Product Status

Vendor	WatchGuard
Product	Fireware OS
Versions	Default: unaffected affected from 2026.3 to 2026.3.2 (excl.) affected from 2025.0 to 2026.2.3 (excl.) affected from 12.0 to 12.12.3 (excl.)

Exploits

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

Solutions

Fireware OS 2026.3.2, Fireware OS 2026.2.3, Fireware OS 12.12.3

Credits

Laurent GAFFIE, (secorizon.com) finder

References

https://psirt.watchguard.com/CVE-2026-81433

Problem Types

CWE-120 CWE
CWE-121 CWE
CWE-787 CWE