9 Realms Cybersecurity
AdvisoriesCVE-2026-20131

Cisco Secure Firewall Management Center (FMC) Software and Cisco Security Cloud Control (SCC) Firewall Management Deserialization of Untrusted Data Vulnerability

Known Ransomware UseCiscoSecure Firewall Management Center (FMC)Added March 19, 2026

CISA Known Exploited Vulnerabilities Data

Description

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.

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.

CISA Due Date

March 22, 2026 (federal agency requirement)

Known Ransomware Campaign Use

Known — this CVE has been associated with ransomware campaigns.

Notes

https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-fmc-rce-NKhnULJh ; https://nvd.nist.gov/vuln/detail/CVE-2026-20131

External References

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Data sourced from the CISA Known Exploited Vulnerabilities catalog. CISA does not endorse any commercial product or service.