Fireware OS Missing Command Validation allows Authenticated Arbitrary File Modification as Root

published 2026-10-27 12 d ago modified 2026-11-04 4 d ago also EUVD-2026-111149

cvss: 7.2; version 4.0, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 0.4%; EPSS 0.4% chance of exploitation in 30 days, percentile 30%
public exploits: 0; none known

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.

Patch / fix

fixed in 1

WatchGuard Fireware OS 12.5.22, 12.12.4, 2026.4

CISA SSVC

Exploitation: none
Automatable: no
Technical impact: partial
Assessed: 4 d ago (2026-11-04)

Exploit prediction

0.36% chance of exploitation in the next 30 days, higher than 30% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by	version	score	vector
CNA	4.0	7.2	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
CNA	4.0	7.2	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/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

Affected products

WatchGuard Fireware OS

Classification

Weakness

CWE-59 Improper Link Resolution Before File Access
CWE-73 External Control of File Name or Path
CWE-732 Incorrect Permission Assignment for Critical Resource

References

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

Sources

CVE List CVE-2026-90464
NVD CVE-2026-90464

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

Summary