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7.1
HIGH CVSS 3.1
CVE-2026-86105
Fireware OS Improper Authorization in Access Portal Reverse Proxy
Overview
Description

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.

Details
INFO

Published Date :

Sept. 30, 2026, 12:16 a.m.

Last Modified :

Oct. 6, 2026, 8:47 p.m.

Remotely Exploit :

Yes !

Source :

5d1c2695-1a31-4499-88ae-e847036fd7e3
Impact
Affected Products

The following products are affected by CVE-2026-86105 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

ID Vendor Product Action
1 Watchguard fireware
2 Watchguard fireware_os
: Total Affected Vendor : 1 | Products : 2
Scoring
CVSS Scores
The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.
Score Version Severity Vector Exploitability Score Impact Score Source
CVSS 134c704f-9b21-4f2e-91b3-4a467353bcc0
CVSS 3.1 HIGH [email protected]
CVSS 4.0 MEDIUM 5d1c2695-1a31-4499-88ae-e847036fd7e3
Solution
Update Fireware OS to fix an authorization bypass in the Access Portal reverse proxy.
  • Update Fireware OS to the latest version.
  • Apply vendor-supplied security patches.
  • Review Access Portal user privileges.
  • Test resource access controls.
References
References to Advisories, Solutions, and Tools

Here, you will find a curated list of external links that provide in-depth information, practical solutions, and valuable tools related to CVE-2026-86105.

URL Resource
https://psirt.watchguard.com/CVE-2026-86105 Patch Vendor Advisory
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-86105 is associated with the following CWEs:

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2026-86105 weaknesses.

CAPEC-64: Using Slashes and URL Encoding Combined to Bypass Validation Logic Using Slashes and URL Encoding Combined to Bypass Validation Logic CAPEC-76: Manipulating Web Input to File System Calls Manipulating Web Input to File System Calls CAPEC-78: Using Escaped Slashes in Alternate Encoding Using Escaped Slashes in Alternate Encoding CAPEC-79: Using Slashes in Alternate Encoding Using Slashes in Alternate Encoding CAPEC-126: Path Traversal Path Traversal CAPEC-71: Using Unicode Encoding to Bypass Validation Logic Using Unicode Encoding to Bypass Validation Logic CAPEC-1: Accessing Functionality Not Properly Constrained by ACLs Accessing Functionality Not Properly Constrained by ACLs CAPEC-5: Blue Boxing Blue Boxing CAPEC-13: Subverting Environment Variable Values Subverting Environment Variable Values CAPEC-17: Using Malicious Files Using Malicious Files CAPEC-39: Manipulating Opaque Client-based Data Tokens Manipulating Opaque Client-based Data Tokens CAPEC-45: Buffer Overflow via Symbolic Links Buffer Overflow via Symbolic Links CAPEC-51: Poison Web Service Registry Poison Web Service Registry CAPEC-59: Session Credential Falsification through Prediction Session Credential Falsification through Prediction CAPEC-60: Reusing Session IDs (aka Session Replay) Reusing Session IDs (aka Session Replay) CAPEC-76: Manipulating Web Input to File System Calls Manipulating Web Input to File System Calls CAPEC-77: Manipulating User-Controlled Variables Manipulating User-Controlled Variables CAPEC-87: Forceful Browsing Forceful Browsing CAPEC-104: Cross Zone Scripting Cross Zone Scripting CAPEC-127: Directory Indexing Directory Indexing CAPEC-402: Bypassing ATA Password Security Bypassing ATA Password Security CAPEC-647: Collect Data from Registries Collect Data from Registries CAPEC-668: Key Negotiation of Bluetooth Attack (KNOB) Key Negotiation of Bluetooth Attack (KNOB)

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2026-86105 vulnerability anywhere in the article.

Results are limited to the first 20 news articles due to potential performance issues.

The following table lists the changes that have been made to the CVE-2026-86105 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • Initial Analysis by [email protected]

    Oct. 06, 2026

    Action Type Old Value New Value
    Added CVSS V3.1 AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:N
    Added CPE Configuration OR *cpe:2.3:o:watchguard:fireware:*:*:*:*:*:*:*:* versions from (including) 12.0 up to (excluding) 12.5.21 *cpe:2.3:o:watchguard:fireware:*:*:*:*:*:*:*:* versions from (including) 12.12 up to (excluding) 12.12.3 *cpe:2.3:o:watchguard:fireware:*:*:*:*:*:*:*:* versions from (including) 2026.3 up to (excluding) 2026.3.2 *cpe:2.3:o:watchguard:fireware:*:*:*:*:*:*:*:* versions from (including) 2025.0 up to (excluding) 2026.2.3
    Added Reference Type WatchGuard Technologies, Inc.: https://psirt.watchguard.com/CVE-2026-86105 Types: Patch, Vendor Advisory
  • CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0

    Sep. 30, 2026

    Action Type Old Value New Value
    Added SSVC {'id': 'CVE-2026-86105', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'none'}, {'automatable': 'no'}, {'technicalImpact': 'partial'}], 'version': '2.0.3', 'timestamp': '2026-09-30T14:39:57.813731Z'}
  • New CVE Received by 5d1c2695-1a31-4499-88ae-e847036fd7e3

    Sep. 30, 2026

    Action Type Old Value New Value
    Added Description 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.
    Added CVSS V4.0 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
    Added CWE CWE-22
    Added CWE CWE-285
    Added CWE CWE-176
    Added Affected New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/86xxx/CVE-2026-86105.json">CVE-2026-86105</a>
    Added Reference https://psirt.watchguard.com/CVE-2026-86105
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.
CVSS
Vulnerability Scoring Details
Base CVSS Score: 6.0
Attack Vector
Attack Complexity
Attack Requirements
Privileges Required
User Interaction
VS Confidentiality
VS Integrity
VS Availability
SS Confidentiality
SS Integrity
SS Availability
Base CVSS Score: 7.1
Attack Vector
Attack Complexity
Privileges Required
User Interaction
Scope
Confidentiality Impact
Integrity Impact
Availability Impact