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.
- Exploited in the wild
- Not known
- Login needed
- An administrator
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- None listed
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
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.
Upgrade, and pass arguments to programs as a list instead of through a shell. More about Command injection.
Is CVE-2026-20099 being exploited?
There is no known exploitation of CVE-2026-20099 in the wild and no public exploit code.
Sources
Also known as GHSA-687g-rcf9-r6r3.