# CVE-2026-90464: WatchGuard Fireware OS path traversal in diagnostic command

Source: https://junglewise.ai/threats/cve-2026-90464-an-external-control-of-file-path-vulnerability-in-a-watchguard  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-10-27. Updated: 2026-10-27  
License: CC BY 4.0 with a link back

CVE-2026-90464 · Severity: info · Published 2026-10-27

A firewall management interface in WatchGuard Fireware OS contains a flaw that allows authenticated administrators with read-only access to create, modify, or truncate critical system files with root privileges. An attacker with console or CLI access could manipulate kernel parameters and system configurations, potentially leading to firewall compromise or denial of service.

Technologies: [Watchguard Fireware OS](https://junglewise.ai/threats/technologies/fireware-os). Vendors: [Watchguard](https://junglewise.ai/threats/vendors/watchguard).

## Quick answers

**Is CVE-2026-90464 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-90464 being exploited in the wild.

**How severe is CVE-2026-90464?** Informational severity, published 27 October 2026.

**Which products and versions are affected?** Watchguard Fireware OS Default: 2025.1–2026.3, 12.0–12.12.3; T15/T35: 12.0–12.5.21.

**Is there a fix for CVE-2026-90464?** Yes: fixed in Fireware OS 2026.4, Fireware OS 12.12.4, Fireware OS 12.5.22. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-90464 attacked?** It is attacked over the network, in a network appliance.

**Am I affected by CVE-2026-90464?** 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

## Technical details

An external control of file path vulnerability (CWE-73, CWE-59) in a diagnostic command allows authenticated users with Device Monitor privileges to bypass path validation and write arbitrary numeric values to system files. The vulnerability requires remote access to the management CLI with valid credentials; written content is constrained to numeric values but can still modify kernel parameters and configuration files as root.

## Affected products

- WatchGuard Fireware OS Default: 2025.1–2026.3, 12.0–12.12.3; T15/T35: 12.0–12.5.21

## Timeline

- 2026-10-27: disclosed

## References

- [https://psirt.watchguard.com/CVE-2026-90464](https://psirt.watchguard.com/CVE-2026-90464)

## Related threats

- [WatchGuard Fireware OS integer overflow in WebSocket Access Portal](https://junglewise.ai/threats/cve-2026-93866-an-integer-overflow-vulnerability-in-the-websocket-connection)
- [WatchGuard Fireware OS authentication bypass in FireCluster daemon](https://junglewise.ai/threats/cve-2026-93865-a-missing-authentication-vulnerability-in-the-fireware-os)
- [WatchGuard Fireware OS arbitrary file overwrite via link following](https://junglewise.ai/threats/cve-2026-93864-a-link-following-vulnerability-in-watchguard-fireware-os-s)
- [WatchGuard Fireware OS out-of-bounds read in FireCluster Sync](https://junglewise.ai/threats/cve-2026-93862-an-out-of-bounds-read-vulnerability-in-the-firecluster-sync)
- [WatchGuard Fireware OS stack buffer overflow in SIP proxy](https://junglewise.ai/threats/cve-2026-93857-a-stack-based-buffer-overflow-vulnerability-in-fireware-os-s-sip)