Vulnerability · Published Oct 27, 2026 · Assigned by WatchGuard

CVE-2026-90464Fireware OS Missing Command Validation allows Authenticated Arbitrary File Modification as Root

High 7.2

In plain English

A high-severity incorrect permission assignment in Fireware OS from WatchGuard. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 30% of all known vulnerabilities).

Severity (CVSS 4.0)7.2High

Exploit odds (30 days)0.4%top 69.6% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

Official description

An external control of file path vulnerability in a WatchGuard Fireware OS firewall diagnostic command allows a remote, authenticated attacker with at least read-only (Device Monitor) privileges and access to the management CLI to create, truncate, or overwrite arbitrary files and modify kernel parameters with root privileges by submitting a specially crafted command. Written content is limited to numeric values.

Affected products (as reported)

Vendor	Product	Versions
WatchGuard	Fireware OS	2025.1 – before 2026.412.0 – before 12.12.4
WatchGuard	Fireware OS	12.0 – before 12.5.22

Weakness: CWE-59, CWE-73, CWE-732 · Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:H/VA:H/SC:N/SI:N/SA:N

References

https://psirt.watchguard.com/CVE-2026-90464 vendor-advisory