CVE-2026-20340
Cisco Secure Firewall Management Center Software Deserialization Arbitrary Root Command Execution Vulnerability
A vulnerability in Cisco Secure FMC Software could allow an authenticated, remote attacker to execute arbitrary commands at the root privilege level. This vulnerability is due to unsecured deserialization of web-management user-controlled data. An attacker could exploit this vulnerability by authenticating to the device and sending a crafted HTTP payload. A successful exploit could allow the attacker to save the crafted payload and then execute it on the underlying operating system as root. To exploit this vulnerability, the attacker must have valid credentials for a user account with at least the role of Security Analyst (read-only).
| CWE | CWE-502 |
| Vendor | cisco |
| Product | cisco secure firewall management center (fmc) |
| Ecosystems | |
| Industries | NetworkingTelecommunications |
| Published | Sep 16, 2026 |
Get instant alerts for cisco cisco secure firewall management center (fmc)
Be the first to know when new high vulnerabilities affecting cisco cisco secure firewall management center (fmc) are published — delivered to Slack, Telegram or Discord.
CVSS v3 Breakdown
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H