# CVE-2026-20324: Cisco Secure Firewall Management Center sftunnel Root Arbitrary Code Exectution Vulnerability

> Authenticated attackers can execute arbitrary commands as root by exploiting incorrect permissions in the sftunnel protocol of Cisco FMC.

- **Severity:** Critical 9.9 (`CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 16 Sep 2026
- **Updated:** 18 Sep 2026
- **Also known as:** GHSA-m3pq-vq89-c8m5

## What is CVE-2026-20324?

CVE-2026-20324 is a critical missing authorization vulnerability in Cisco Secure Firewall Management Center (FMC), published on 16 Sep 2026. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

A vulnerability in the sftunnel inter-device communication protocol of Cisco Secure Firewall Management Center (FMC) Software could allow an authenticated, remote attacker to execute arbitrary commands as root.

This vulnerability exists because a registered sftunnel peer has incorrect permissions to write an arbitrary file to any location on the device. An attacker could exploit this vulnerability by hijacking the sftunnel communication connection or being a valid registered sftunnel peer and sending an sftunnel command to write a malicious file to the disk of an affected device. A successful exploit could allow the attacker to write a file to the device that is executed with root privileges. To exploit this vulnerability, the attacker must have valid user credentials on the affected device.

Weakness: CWE-862 (Missing Authorization)

## Which versions are affected by CVE-2026-20324?


## How do I fix CVE-2026-20324?

No fix has been published for CVE-2026-20324 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-20324 being exploited?

There is no known exploitation of CVE-2026-20324 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-20324 and fix it if it is affected.

What it is: CVE-2026-20324 is a critical missing authorization vulnerability in Cisco Secure Firewall Management Center (FMC), published on 16 Sep 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-20324 in the wild and no public exploit code.

Affected product: Cisco Secure Firewall Management Center (FMC). 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-2026-20324/ (Markdown: https://insights.sbomify.com/CVE-2026-20324/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-20324
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-20324
- OSV: https://osv.dev/vulnerability/CVE-2026-20324

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-20324/
Summaries are generated and may contain mistakes; the official description above is the record.