CVE-2026-20242 PUBLISHED

Cisco Secure Firewall Management Center Software Java Deserialization Remote Code Execution Vulnerability

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

A vulnerability in the External Database Access feature of Cisco Secure Firewall Management Center (FMC) Software could allow an unauthenticated, remote attacker to execute arbitrary commands as root on an affected device.

This vulnerability is due to insecure deserialization of a user-supplied Java byte stream from a host that is configured in the external database access list. An attacker could exploit this vulnerability by sending a crafted, serialized Java byte stream to a specific TCP port of an affected device. A successful exploit could allow the attacker to execute arbitrary commands on the device and elevate privileges to root. Notes:

This vulnerability can be exploited only by an attacker who has control of a host in the external database access list. If the FMC management interface does not have public internet access, the attack surface that is associated with this vulnerability is reduced.

Metrics

CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
CVSS Score: 9.8

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 vulnerability that is described in this advisory.

References

Problem Types

  • Deserialization of Untrusted Data cwe