CVE-2026-20340 PUBLISHED

Cisco Secure Firewall Management Center Software Deserialization Arbitrary Root Command Execution Vulnerability

Assigner: cisco
Reserved: 08.10.2025 Published: 16.09.2026 Updated: 16.09.2026

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).

Metrics

CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
CVSS Score: 8.8

Product Status

Vendor Cisco
Product Cisco Secure Firewall Management Center (FMC)
Versions Default: unknown
  • Version 7.0.0 is affected
  • Version 7.0.0.1 is affected
  • Version 7.0.1 is affected
  • Version 7.0.1.1 is affected
  • Version 7.0.2 is affected
  • Version 7.2.0 is affected
  • Version 7.0.2.1 is affected
  • Version 7.0.3 is affected
  • Version 7.2.0.1 is affected
  • Version 7.0.4 is affected
  • Version 7.2.1 is affected
  • Version 7.0.5 is affected
  • Version 7.3.0 is affected
  • Version 7.2.2 is affected
  • Version 7.3.1 is affected
  • Version 7.2.3 is affected
  • Version 7.2.3.1 is affected
  • Version 7.2.4 is affected
  • Version 7.0.6 is affected
  • Version 7.2.4.1 is affected
  • Version 7.2.5 is affected
  • Version 7.3.1.1 is affected
  • Version 7.4.0 is affected
  • Version 7.0.6.1 is affected
  • Version 7.2.5.1 is affected
  • Version 7.4.1 is affected
  • Version 7.2.6 is affected
  • Version 7.4.1.1 is affected
  • Version 7.0.6.2 is affected
  • Version 7.2.7 is affected
  • Version 7.2.5.2 is affected
  • Version 7.3.1.2 is affected
  • Version 7.2.8 is affected
  • Version 7.6.0 is affected
  • Version 7.4.2 is affected
  • Version 7.2.8.1 is affected
  • Version 7.0.6.3 is affected
  • Version 7.4.2.1 is affected
  • Version 7.2.9 is affected
  • Version 7.0.7 is affected
  • Version 7.7.0 is affected
  • Version 7.4.2.2 is affected
  • Version 7.2.10 is affected
  • Version 7.6.1 is affected
  • Version 7.4.2.3 is affected
  • Version 7.0.8 is affected
  • Version 7.6.2 is affected
  • Version 7.7.10 is affected
  • Version 7.2.10.1 is affected
  • Version 7.0.8.1 is affected
  • Version 7.6.2.1 is affected
  • Version 7.2.10.2 is affected
  • Version 7.7.10.1 is affected
  • Version 7.4.2.4 is affected
  • Version 7.4.3 is affected
  • Version 7.6.3 is affected
  • Version 7.7.11 is affected
  • Version 7.6.4 is affected
  • Version 10.0.0 is affected
  • Version 7.4.4 is affected
  • Version 7.4.5 is affected
  • Version 7.0.9 is affected
  • Version 7.2.11 is affected
  • Version 7.7.12 is affected
  • Version 7.6.5 is affected
  • Version 7.4.6 is affected
  • Version 10.0.1 is affected
  • Version 7.4.7 is affected

Exploits

The Cisco Product Security Incident Response Team (PSIRT) is not aware of any public announcements or malicious use of the vulnerabilities that are described in this advisory.

References

Problem Types

  • Deserialization of Untrusted Data cwe