# CVE-2026-20099: Cisco UCS Manager and FXOS Software Command Injection Vulnerability

> An authenticated local attacker with admin privileges can execute arbitrary commands as root via command injection in Cisco FXOS and UCS Manager.

- **Severity:** Medium 6.7 (`CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** An administrator
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 25 Feb 2026
- **Updated:** 26 Feb 2026
- **Also known as:** GHSA-687g-rcf9-r6r3

## What is CVE-2026-20099?

CVE-2026-20099 is a medium-severity command injection vulnerability in Cisco Firepower Extensible Operating System (FXOS), published on 25 Feb 2026. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

A vulnerability in the web-based management interface of Cisco FXOS Software and Cisco UCS Manager Software could allow an authenticated, local attacker with administrative privileges to perform command injection attacks on an affected system and elevate privileges to root. 

This vulnerability is due to insufficient input validation of command arguments supplied by the user. An attacker could exploit this vulnerability by authenticating to a device and submitting crafted input to the affected command. A successful exploit could allow the attacker to execute arbitrary commands on the underlying operating system of the affected device with root-level privileges.

Weakness: CWE-78 (Improper Neutralization of Special Elements used in an OS Command)

## Which versions are affected by CVE-2026-20099?


## How do I fix CVE-2026-20099?

No fix has been published for CVE-2026-20099 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-20099 being exploited?

There is no known exploitation of CVE-2026-20099 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-20099 and fix it if it is affected.

What it is: CVE-2026-20099 is a medium-severity command injection vulnerability in Cisco Firepower Extensible Operating System (FXOS), published on 25 Feb 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-2026-20099 in the wild and no public exploit code.

Affected product: Cisco Firepower Extensible Operating System (FXOS). 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-2026-20099/ (Markdown: https://insights.sbomify.com/CVE-2026-20099/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-20099
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-20099
- OSV: https://osv.dev/vulnerability/CVE-2026-20099

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From sbomify Insights: https://insights.sbomify.com/CVE-2026-20099/
Summaries are generated and may contain mistakes; the official description above is the record.