WatchGuard TechnologiesCVE-2026-81433

WatchGuard Technologies Fireware OS: stack buffer overflow

High8.7CVE-2026-81433 · Published Sep 30, 2026 · updated Oct 1, 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.

WatchGuard Technologies advisory

Affected versions

Package	Affected	Fixed in
Fireware OS Product	>= 2026.3, < 2026.3.2	2026.3.2
	>= 2025.0, < 2026.2.3	2026.2.3
	>= 12.0, < 12.12.3	12.12.3

Details and references

CVSS 4.0: 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/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
Severity from: the vendor (its own CVE record or advisory)
Weakness: CWE-120, CWE-121, CWE-787

More WatchGuard Technologies advisories

All WatchGuard Technologies

Date	Advisory	Severity	Fixed in
Sep 30	WatchGuard Technologies Fireware OS: null pointer dereference High8.7Sep 30 CVE-2026-861342026.3.2+3 more	High8.7	2026.3.2+3 more
Sep 30	WatchGuard Technologies Fireware OS: integer overflow High8.2Sep 30 CVE-2026-861332026.3.2+3 more	High8.2	2026.3.2+3 more
Sep 30	WatchGuard Technologies Fireware OS: missing authorization High7.1Sep 30 CVE-2026-861362026.3.2+3 more	High7.1	2026.3.2+3 more
Sep 30	WatchGuard Technologies Fireware OS: missing authorization High7.1Sep 30 CVE-2026-904412026.3.2+3 more	High7.1	2026.3.2+3 more
Sep 30	WatchGuard Technologies Fireware OS: stack buffer overflow High8.6Sep 30 CVE-2026-181452026.3.2+3 more	High8.6	2026.3.2+3 more
Sep 30	WatchGuard Technologies Fireware OS: improper authorization High7.2Sep 30 CVE-2026-861012026.3.2+3 more	High7.2	2026.3.2+3 more

Affected versions

More WatchGuard Technologies advisories

Critical advisories by email