CVE-2026-20131 — Cisco Secure Firewall Management Center (FMC) Software and Cisco Security Cloud Control (SCC) Firewall Management Deserialization of Untrusted Data Vulnerability

Exploitation status

CVE-2026-20131 is listed in the CISA Known Exploited Vulnerabilities (KEV) catalog, added 2026-03-19. Cisco Secure Firewall Management Center (FMC) Software and Cisco Security Cloud Control (SCC) Firewall Management contain a deserialization of untrusted data vulnerability in the web-based management interface that could allow an unauthenticated, remote attacker to execute arbitrary Java code as root on an affected device.

Advisory facts

Vendor or project

Cisco

Affected product

Secure Firewall Management Center (FMC)

Added to CISA KEV

2026-03-19

US federal remediation due date

2026-03-22

Ransomware association

Known

EPSS score

27.6% chance of exploitation in 30 days

Weakness (CWE)

CWE-502

Remediation: the required action

Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.

Wording published by CISA for this catalog entry. It is the baseline action, not a decision about your environment: whether this exposure matters for you depends on where the affected component runs, what it is exposed to and who owns it.

From advisory to a decision you can defend

A catalog entry tells you a vulnerability is being exploited somewhere. It does not tell you whether it matters in your estate, who owns the fix, or what evidence an auditor will ask for later. That is the work VulnTrek does: it takes findings from the tools you already run, decides which exposure actually matters, routes it to an owner, keeps remediation human-approved and retains the lineage as evidence.