Is CVE-2026-90465 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2026-90465 being exploited in the wild.

How severe is CVE-2026-90465?

Informational severity, published 27 October 2026.

Which products and versions are affected?

Watchguard Fireware OS Versions before 2026.4 (2025.1 through 2026.3) and before 12.12.4 (12.0 through 12.12.3) on Default and T15/T35 models; T15/T35 also affected before 12.5.22.

How is CVE-2026-90465 attacked?

It is attacked over the network or from the adjacent network, in a network appliance.

Am I affected by CVE-2026-90465?

Check whether you run Watchguard Fireware OS at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

CVE-2026-90465: WatchGuard Fireware OS missing authentication in FireCluster Sync

CVE-2026-90465 · Severity: info · Published 2026-10-27

WatchGuard Fireware OS, a firewall protecting corporate networks, contains a missing authentication flaw in its FireCluster Sync feature that allows an attacker with network access to the cluster interconnect to execute privileged firewall management commands as root. An exploited vulnerability could allow an attacker to compromise firewall configuration, disable security policies, or gain complete control of the firewall appliance. This vulnerability only affects Firebox appliances configured as members of a FireCluster.

Technologies: Watchguard Fireware OS. Vendors: Watchguard.

Quick answers

Is CVE-2026-90465 exploited in the wild?: No. Junglewise Threat Intelligence has no report of CVE-2026-90465 being exploited in the wild.
How severe is CVE-2026-90465?: Informational severity, published 27 October 2026.
Which products and versions are affected?: Watchguard Fireware OS Versions before 2026.4 (2025.1 through 2026.3) and before 12.12.4 (12.0 through 12.12.3) on Default and T15/T35 models; T15/T35 also affected before 12.5.22.
Is there a fix for CVE-2026-90465?: Yes: fixed in Fireware OS 2026.4, Fireware OS 12.12.4, Fireware OS 12.5.22. Until then: This vulnerability only affects Firebox appliances configured as members of a FireCluster, so systems not using FireCluster are not at risk. Restrict network access to the cluster interconnect to trusted infrastructure and ensure cluster peers are properly secured against compromise. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-90465 attacked?: It is attacked over the network or from the adjacent network, in a network appliance.
Am I affected by CVE-2026-90465?: Check whether you run Watchguard Fireware OS at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

How to fix

Fixed in: Fireware OS 2026.4, Fireware OS 12.12.4, Fireware OS 12.5.22

This vulnerability only affects Firebox appliances configured as members of a FireCluster, so systems not using FireCluster are not at risk. Restrict network access to the cluster interconnect to trusted infrastructure and ensure cluster peers are properly secured against compromise.

Technical details

A missing authentication vulnerability in FireCluster Sync processing (CWE-306, CWE-290) allows an attacker positioned on the cluster interconnect network to send specially crafted requests and invoke privileged root-level firewall management actions. The attack requires network access to the cluster interconnect, which could be achieved by compromising a cluster peer or through an on-path network position. Successful exploitation grants the attacker root-level command execution on the firewall appliance.

Affected products

WatchGuard Fireware OS Versions before 2026.4 (2025.1 through 2026.3) and before 12.12.4 (12.0 through 12.12.3) on Default and T15/T35 models; T15/T35 also affected before 12.5.22

Timeline

2026-10-27: disclosed

References

https://psirt.watchguard.com/CVE-2026-90465

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