Fireware OS Improper Authorization in Access Portal Reverse Proxy

published 2026-09-29 40 d ago modified 2026-10-06 33 d ago also EUVD-2026-89492

cvss: 7.1; version 3.1, NVD
cisa kev: Not listed; not in CISA's catalog
epss: 0.3%; EPSS 0.3% chance of exploitation in 30 days, percentile 23%
public exploits: 0; none known

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.

Patch / fix

fixed in 1 links 1

WatchGuard Fireware OS 12.5.21, 12.12.3, 2026.2.3, 2026.3.2

psirt.watchguard.com/CVE-2026-86105 advisory

CISA SSVC

Exploitation: none
Automatable: no
Technical impact: partial
Assessed: 39 d ago (2026-09-30)

Exploit prediction

0.31% chance of exploitation in the next 30 days, higher than 23% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by	version	score	vector
CNA	4.0	5.3	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
CNA	4.0	6.0	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/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
NVD	3.1	7.1	CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:N

Affected products

WatchGuard Fireware OS

Classification

Weakness

CWE-176 Improper Handling of Unicode Encoding
CWE-22 Improper Limitation of a Pathname to a Restricted Directory
CWE-285 Improper Authorization

References

psirt.watchguard.com /CVE-2026-86105
vendor-advisory, patch

Sources

CVE List CVE-2026-86105
NVD CVE-2026-86105

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