Authentication bypass in Brocade Fabric OS web management interface
Key facts
- Attack vector
- Adjacent network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Attack requirements
- None
- Impact type
- Security bypass
- Confidentiality · integrity · availability
- Low · None · None
- Fix status
- Fixed
Attack profile from CVSS 4.0 · CNA. Fix status from CNA. Impact type from CWE-290.
Summary
Brocade Fabric OS versions before 10.0.1 contain an authentication bypass in the web server management interface. The web dispatcher trusts the client-supplied HTTP host header instead of the actual socket source IP when deciding management VLAN trust, which is a form of authentication bypass by spoofing (CWE-290). An unauthenticated remote attacker over an adjacent network can bypass IP-filtering access control lists and obtain sensitive device metadata such as model, serial number, hardware revision, and firmware version.
Written with Claude Haiku 5.5 from the sources below · 2026-10-29
Description from the CNA
An authentication and access control bypass vulnerability exists in the web server management interface of Brocade Fabric OS versions before 10.0.1. The web dispatcher routine evaluates internal management VLAN trust decisions using the client-supplied HTTP host header instead of the actual socket transport layer source IP address. Successful exploitation allows the attacker to bypass IP-filtering access control lists (ACLs) and obtain sensitive device metadata (such as model, serial number, hardware revision, and firmware version) without authentication.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
Remediation
Fabric OS versions from 0 before 10.0.1 are affected, and 10.0.1 fixes the flaw. The sources list no fixed version for other Fabric OS branches.
Written with Claude Haiku 5.5 from the sources below · 2026-10-29
- Fix · CNA Fabric OS (Brocade) Fixed in 10.0.1
Fixed in the same release
Records fixed by the same vendor advisory or release, as the CNA lists them.
- Release ·
Brocade Fabric OS 10.0.1
22 records Highest priority Priority MEDIUM 4 MEDIUM, 18 LOW
Other records, highest priority first
- TI-2026-69336 OS command injection in Brocade Fabric OS management interfacePriority MEDIUM 43
- TI-2026-69334 Command injection in Brocade Fabric OS REST API management interfacePriority MEDIUM 43
- TI-2026-69348 Stack-based buffer overflow in Brocade Fabric OS SNMP daemonPriority MEDIUM 40
Timeline
- 2026-10-08 Threatist record created from CVE-2026-87686
- 2026-10-08 Alias added: GHSA-3whm-p6mj-fpf5
- 2026-10-08 CISA SSVC decision points changed
- 2026-10-14 CVSS score added · NVD
References
More Brocade vulnerabilities
- TI-2025-01721 Code injection exposure in Fabric OS 9.1.0 through 9.1.1d6 KEVCVSS 4.0HIGH 8.6
- TI-2016-06760 Path traversal in Brocade Network Advisor versions released prior to and including 14.0.2 CVSS 3.0CRITICAL 9.8
- TI-2024-19729 hard-coded credentials in the documentation that appear as the appliance root password CVSS 3.1CRITICAL 9.8
- TI-2016-06762 Path traversal in Brocade Network Advisor versions released prior to and including 14.0.2 CVSS 3.0HIGH 7.5
- TI-2018-04739 OS command injection in Brocade Network Advisor CVSS 3.0CRITICAL 9.8
- TI-2016-06761 Path traversal in Brocade Network Advisor versions released prior to and including 14.0.2 CVSS 3.0HIGH 7.5
Sources
- CVE-2026-87686 · CVE Program
- CVE-2026-87686 · NVD
- FIRST EPSS
- GHSA-3whm-p6mj-fpf5 · GitHub Advisory Database · CC BY 4.0
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