CVE-2026-86105: CWE-176 in WatchGuard Fireware OS
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.
AI Analysis
Technical Summary
This vulnerability (CVE-2026-86105) in WatchGuard Fireware OS arises from improper authorization in the Access Portal reverse proxy component. An authenticated user with limited privileges can exploit this flaw by crafting requests to access other web applications beyond their authorization scope. The issue is tracked under CWE-176 (Improper Handling of Unicode Encoding) and related CWEs indicating authorization weaknesses. The vulnerability affects versions >=12.0 <12.5.21, >=12.0 <12.12.3, >=2025.0 <2026.2.3, and >=2026.3 <2026.3.2. No known exploits are reported in the wild, and no vendor patch links are provided in the data.
Potential Impact
An attacker with low-privileged authenticated access to the Access Portal can gain unauthorized access to other web applications within the portal. This could lead to unauthorized information disclosure or access escalation within the affected environment. The CVSS 4.0 score of 5.3 reflects a medium impact, with network attack vector, low attack complexity, and partial privileges required.
Mitigation Recommendations
Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. No official patch or fix links are provided in the available data. Until a patch is available, restrict Access Portal user privileges carefully and monitor for unusual access patterns. Follow vendor advisories for updates.
CVE-2026-86105: CWE-176 in WatchGuard Fireware OS
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.
CVSS v4.0
Score 5.3medium
Affected software
WatchGuard
Fireware OS
WatchGuard
Fireware OS
pkg:github/watchguard/fireware-osRun on your own infrastructure? Check whether these packages are installed with threat-finder — our free open-source scanner.
Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
This vulnerability (CVE-2026-86105) in WatchGuard Fireware OS arises from improper authorization in the Access Portal reverse proxy component. An authenticated user with limited privileges can exploit this flaw by crafting requests to access other web applications beyond their authorization scope. The issue is tracked under CWE-176 (Improper Handling of Unicode Encoding) and related CWEs indicating authorization weaknesses. The vulnerability affects versions >=12.0 <12.5.21, >=12.0 <12.12.3, >=2025.0 <2026.2.3, and >=2026.3 <2026.3.2. No known exploits are reported in the wild, and no vendor patch links are provided in the data.
Potential Impact
An attacker with low-privileged authenticated access to the Access Portal can gain unauthorized access to other web applications within the portal. This could lead to unauthorized information disclosure or access escalation within the affected environment. The CVSS 4.0 score of 5.3 reflects a medium impact, with network attack vector, low attack complexity, and partial privileges required.
Mitigation Recommendations
Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. No official patch or fix links are provided in the available data. Until a patch is available, restrict Access Portal user privileges carefully and monitor for unusual access patterns. Follow vendor advisories for updates.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- WatchGuard
- Date Reserved
- 2026-09-05T00:16:03.449Z
- Cvss Version
- 4.0
- State
- PUBLISHED
Threat ID: 6abc4826680226ef686df2c8
Added to database: 09/29/2026, 23:22:14 UTC
Last enriched: 09/29/2026, 23:36:47 UTC
Last updated: 09/30/2026, 03:38:29 UTC
Views: 11
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