# CVE-2026-86105: WatchGuard Fireware OS improper authorization in Access Portal reverse proxy

Source: https://junglewise.ai/threats/cve-2026-86105-an-improper-authorization-vulnerability-in-fireware-os-s-access  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-09-30. Updated: 2026-09-30  
License: CC BY 4.0 with a link back

CVE-2026-86105 · Severity: info · Published 2026-09-30

WatchGuard Fireware OS includes an Access Portal reverse proxy component that controls user access to web applications. An authenticated user with limited permissions can craft a specially designed request to bypass access controls and reach web applications they should not be authorized to use, potentially exposing sensitive data or gaining unauthorized system access.

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

## Quick answers

**Is CVE-2026-86105 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-86105 being exploited in the wild.

**How severe is CVE-2026-86105?** Informational severity, published 30 September 2026.

**Which products and versions are affected?** Watchguard Fireware OS 2026.3.x before 2026.3.2; 2026.2.x before 2026.2.3; 2025.0.x; 12.x before 12.12.3; 12.5.x before 12.5.21 (T15/T35 models).

**Is there a fix for CVE-2026-86105?** No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

**How is CVE-2026-86105 attacked?** It is attacked over the network, in a network appliance.

**Am I affected by CVE-2026-86105?** 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.

## Technical details

An improper authorization vulnerability in the Access Portal reverse proxy allows authenticated low-privileged users to access unauthorized web applications by sending specially crafted requests leveraging path traversal or URL encoding bypasses. The vulnerability involves improper pathname handling and authorization checks (CWE-22, CWE-285). Exploitation requires user authentication and network access to the Access Portal; patched versions are available.

## Affected products

- WatchGuard Fireware OS 2026.3.x before 2026.3.2; 2026.2.x before 2026.2.3; 2025.0.x; 12.x before 12.12.3; 12.5.x before 12.5.21 (T15/T35 models)

## Timeline

- 2026-09-29: disclosed

## References

- [https://psirt.watchguard.com/CVE-2026-86105](https://psirt.watchguard.com/CVE-2026-86105)

## 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)