WatchGuard TechnologiesCVE-2026-8247

WatchGuard Technologies Fireware OS: out-of-bounds write

High7.7CVE-2026-8247 · Published Jul 3, 2026 · updated Aug 28, 2026

An Out-of-bounds Write vulnerability in WatchGuard Fireware OS may allow an unauthenticated attacker on the same local network segment to execute arbitrary code. This vulnerability affects Fireware OS 11.0 up to and including 11.12.4_Update1, 12.0 up to and including 12.12 and 2025.1 up to and including 2026.2.

WatchGuard Technologies advisory

Affected versions

Package	Affected	Fixed in
Fireware OS Product	>= 2025.1, < 2026.2.1	2026.2.1
	>= 12.0, < 12.12.1	12.12.1
	<= 11.0	No fix yet
	>= 12.0, < 12.11.9	12.11.9
	>= 12.0, < 12.5.19	12.5.19

Details and references

CVSS 4.0: CVSS:4.0/AV:A/AC:L/AT:P/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-787

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All WatchGuard Technologies

Date	Advisory	Severity	Fixed in
Jul 3	WatchGuard Technologies Fireware OS: improper signature check High8.6Jul 3 CVE-2026-137222026.2.1+2 more	High8.6	2026.2.1+2 more
Jul 3	WatchGuard Technologies Fireware OS: hard-coded credentials Medium5.9Jul 3 CVE-2026-137282026.2.1+2 more	Medium5.9	2026.2.1+2 more
Jul 3	WatchGuard Technologies Fireware OS: denial of service Medium6.9Jul 3 CVE-2026-133712026.2.1+3 more	Medium6.9	2026.2.1+3 more
Jul 3	WatchGuard Technologies Fireware OS: cross-site scripting Medium4.8Jul 3 CVE-2026-133732026.2.1+3 more	Medium4.8	2026.2.1+3 more
Jul 3	WatchGuard Technologies Fireware OS: cross-site scripting Medium4.8Jul 3 CVE-2026-133742026.2.1+3 more	Medium4.8	2026.2.1+3 more
Jul 3	WatchGuard Technologies Fireware OS: cross-site scripting Medium4.8Jul 3 CVE-2026-133752026.2.1+3 more	Medium4.8	2026.2.1+3 more

Affected versions

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