Fireware OS Missing Authentication in FireCluster Sync Allows Privilege Escalation

published 2026-10-27 12 d ago modified 2026-10-29 11 d ago also EUVD-2026-111146

cvss: 9.4; version 4.0, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 0.2%; EPSS 0.2% chance of exploitation in 30 days, percentile 14%
public exploits: 0; none known

A missing authentication vulnerability in the FireCluster Sync processing allows an attacker positioned on the cluster interconnect, such as a compromised cluster peer or an on-path network attacker, to invoke privileged firewall management actions as root by sending a specially crafted request.

Patch / fix

fixed in 1

WatchGuard Fireware OS 12.5.22, 12.12.4, 2026.4

CISA SSVC

Exploitation: none
Automatable: no
Technical impact: total
Assessed: 11 d ago (2026-10-29)

Exploit prediction

0.24% chance of exploitation in the next 30 days, higher than 14% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by	version	score	vector
CNA	4.0	8.7	CVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H
CNA	4.0	9.4	CVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H/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-290 Authentication Bypass by Spoofing
CWE-306 Missing Authentication for Critical Functionality
CWE-77 Improper Neutralization of Special Elements used in a Command
CWE-862 Missing Authorization

References

psirt.watchguard.com /CVE-2026-90465
vendor-advisory

Sources

CVE List CVE-2026-90465
NVD CVE-2026-90465

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