# CVE-2026-87686: Auth bypass in Fabric OS

> Attackers can bypass IP-based access controls via Host header spoofing to access sensitive device metadata without authentication in Brocade Fabric OS.

- **Severity:** Medium 5.3 (`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`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 8 Oct 2026
- **Updated:** 8 Oct 2026
- **Also known as:** GHSA-3whm-p6mj-fpf5

## What is CVE-2026-87686?

CVE-2026-87686 is a medium-severity authentication bypass vulnerability in Broadcom Fabric Operating System, published on 8 Oct 2026. It can only be exploited from the same machine or local network, with no action from the victim.

### Official 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.

Weakness: CWE-290 (Authentication Bypass by Spoofing)

## Which versions are affected by CVE-2026-87686?

It affects 1 product.


Products: Broadcom Fabric Operating System.

## How do I fix CVE-2026-87686?

No fix has been published for CVE-2026-87686 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-87686 being exploited?

There is no known exploitation of CVE-2026-87686 in the wild and no public exploit code.

## Other vulnerabilities in Broadcom Fabric Operating System

- [CVE-2025-1976](https://insights.sbomify.com/CVE-2025-1976/): Broadcom Brocade Fabric OS Code Injection (high 8.6, exploited in the wild)
- [CVE-2021-22555](https://insights.sbomify.com/CVE-2021-22555/): Linux Kernel Heap Out-of-Bounds Write (high 8.3, exploited in the wild)
- [CVE-2022-33186](https://insights.sbomify.com/CVE-2022-33186/): Command injection in Brocade Fabric OS (critical 9.8)
- [CVE-2021-27797](https://insights.sbomify.com/CVE-2021-27797/): Hardcoded credentials in Brocade Fabric OS (critical 9.8)
- [CVE-2020-15371](https://insights.sbomify.com/CVE-2020-15371/): Code injection in Brocade Fabric OS (critical 9.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-87686 and fix it if it is affected.

What it is: CVE-2026-87686 is a medium-severity authentication bypass vulnerability in Broadcom Fabric Operating System, published on 8 Oct 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-87686 in the wild and no public exploit code.

Affected product: Broadcom Fabric Operating System. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-87686/ (Markdown: https://insights.sbomify.com/CVE-2026-87686/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-87686
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-87686
- OSV: https://osv.dev/vulnerability/CVE-2026-87686

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-87686/
Summaries are generated and may contain mistakes; the official description above is the record.