By Abinaya
Publication Date: 2026-03-26 11:04:00
Cisco has released an urgent security advisory addressing a critical vulnerability in its Secure Firewall Management Center (FMC) software.
This severe flaw allows unauthenticated remote attackers to execute arbitrary code with full root privileges. CVE-2026-20131 is a critical vulnerability with a CVSS score of 10.0, stemming from insecure deserialization (CWE-502) and is exploitable remotely without requiring any privileges.
The security flaw resides in the web-based management interface of Cisco Secure FMC. The insecure deserialization of a user-supplied Java byte stream directly causes it.
An attacker can exploit this weakness by simply sending a specially crafted serialized Java object to the vulnerable web interface.
If the exploitation is successful, the attacker can execute arbitrary Java code directly on the targeted device. This action allows the malicious actor to elevate their system privileges to full root access.
Gaining root…
