CVE-2026-86105 PUBLISHED

Fireware OS Improper Authorization in Access Portal Reverse Proxy

Assigner: WatchGuard
Reserved: 05.09.2026 Published: 29.09.2026 Updated: 30.09.2026

An improper authorization vulnerability in Fireware OS's Access Portal reverse proxy allows an authenticated, low-privileged Access Portal user to access other web applications they are not authorized for by sending a specially crafted request for a different resource which they are authorized to access.

Metrics

CVSS 4.0

CVSS Vector: CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:L/VA:N/SC:N/SI:N/SA:N
CVSS Score: 5.3

Exploitability Metrics		Vulnerable System Impact Metrics		Subsequent System Impact Metrics
Attack Vector	Network	Confidentiality	High	Confidentiality	None
Attack Complexity	Low	Integrity	Low	Integrity	None
Attack Requirements	Present	Availability	None	Availability	None
Privileges Required	Low
User Interaction	None

CVSS 4.0

Product Status

Vendor	WatchGuard
Product	Fireware OS
Versions	Default: unaffected affected from 2026.3 to 2026.3.2 (excl.) affected from 2025.0 to 2026.2.3 (excl.) affected from 12.0 to 12.12.3 (excl.)

Vendor	WatchGuard
Product	Fireware OS
Versions	Default: unaffected affected from 12.0 to 12.5.21 (excl.)

Affected Configurations

This vulnerability affects Firebox deployments where the Access Portal is configured with multiple reverse-proxy resources.

Exploits

WatchGuard is not aware of any exploitation of this vulnerability in the wild.

Solutions

Fireware OS 2026.3.2, Fireware OS 2026.2.3, Fireware OS 12.12.3, Fireware OS 12.5.21

Credits

WatchGuard AI Security Research finder
Laurent GAFFIE , secorizon.com finder

References

https://psirt.watchguard.com/CVE-2026-86105

Problem Types

CWE-176 CWE
CWE-22 CWE
CWE-285 CWE