Cisco Secure Firewall Management Center (FMC) Software and Cisco Security Cloud Control (SCC) Firewall Management Deserialization of Untrusted Data
What to do
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 deadline 2026-03-22 · passed 5 months ago · applies to US federal civilian agencies; used elsewhere as a reference SLA
What happened
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.
Who is affected
Cisco Secure Firewall Management Center (FMC). Affected version ranges are listed in the vendor advisory and the NVD entry linked under Sources.
Weakness class: CWE-502.
Timeline
- Added to CISA KEVExploitation in the wild confirmed by CISA
- CISA remediation deadlinepassed 5 months ago
Sources
- NVD entry for CVE-2026-20131 nvd.nist.gov/vuln/detail/CVE-2026-20131
- CISA Known Exploited Vulnerabilities catalog www.cisa.gov/known-exploited-vulnerabilities-catalog
- sec.cloudapps.cisco.com sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-fmc-rce-NKhnULJh
- nvd.nist.gov nvd.nist.gov/vuln/detail/CVE-2026-20131