A vulnerability in the web-based management interface of Cisco Secure Firewall Management Center (FMC) Software could allow an unauthenticated, remote attacker to execute arbitrary Java code as root on an affected device. This vulnerability is due to insecure deserialization of a user-supplied Java byte stream. An attacker could exploit this vulnerability by sending a crafted serialized Java object to the web-based management interface of an affected device. A successful exploit could allow the attacker to execute arbitrary code on the device and elevate privileges to root. Note: If the FMC management interface does not have public internet access, the attack surface that is associated with this vulnerability is reduced.
History

Wed, 04 Mar 2026 17:30:00 +0000

Type Values Removed Values Added
Description A vulnerability in the web-based management interface of Cisco Secure Firewall Management Center (FMC) Software could allow an unauthenticated, remote attacker to execute arbitrary Java code as root on an affected device. This vulnerability is due to insecure deserialization of a user-supplied Java byte stream. An attacker could exploit this vulnerability by sending a crafted serialized Java object to the web-based management interface of an affected device. A successful exploit could allow the attacker to execute arbitrary code on the device and elevate privileges to root. Note: If the FMC management interface does not have public internet access, the attack surface that is associated with this vulnerability is reduced.
Weaknesses CWE-502
References
Metrics cvssV3_1

{'score': 10, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H'}


cve-icon MITRE

Status: PUBLISHED

Assigner: cisco

Published:

Updated: 2026-03-04T17:17:56.008Z

Reserved: 2025-10-08T11:59:15.380Z

Link: CVE-2026-20131

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-03-04T18:16:27.153

Modified: 2026-03-04T18:16:27.153

Link: CVE-2026-20131

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

No data.