CVE-2026-87686

Unauthenticated metadata disclosure via spoofed Host header

Published Oct 8, 2026 · Updated Oct 8, 2026

Authentication bypass in Brocade Fabric OS before 10.0.1 allows remote attackers to read switch metadata through the web management interface. Its web dispatcher uses the client-supplied HTTP Host header rather than the socket source IP address to decide whether a request originates on a trusted management VLAN. An attacker with adjacent-network access can bypass IP-filtering ACLs without logging in and obtain the device model, serial number, hardware revision, and firmware version.

CVSS severity5.3
Medium
EPSS probability0.18%
Next 30 days · Oct 19, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Get started

Summary

What happened

Authentication bypass in Brocade Fabric OS before 10.0.1 allows remote attackers to read switch metadata through the web management interface. Its web dispatcher uses the client-supplied HTTP Host header rather than the socket source IP address to decide whether a request originates on a trusted management VLAN. An attacker with adjacent-network access can bypass IP-filtering ACLs without logging in and obtain the device model, serial number, hardware revision, and firmware version.

The record

CVE
CVE-2026-87686
Published
Oct 8, 2026
Updated
Oct 8, 2026
Vendor
Brocade Communications Systems
Product
Fabric OS
Classifications
CWE-290, T1592.003
Attack vector
adjacent
Privileges
unauthenticated

Timeline

How it unfolded

  1. Oct 8, 2026CVE publishedPublication date reported by the CVE source.
  2. Oct 8, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=0 <10.0.1

What conditions does exploitation require?

Attack vectoradjacent
Required privilegesunauthenticated

What is affected?

Brocade Communications Systems · Fabric OSversion=0 <10.0.1

Published CVSS scores

5.3BroadcomCVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Activity data is delayed. The latest report is Sep 28, 2026.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 22, 2026Sep 28, 2026
Latest reporting daySep 28, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectoradjacent
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-290Authentication Bypass by Spoofing
T1592.003Gather Victim Host Information: Firmware

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

See the directory against your own environment.

Your stack

Check the software in your environment

Get started to see how Hinoki identifies affected software and validates exploitability in your environment.

Get started