CVE-2026-20131
Cisco Secure Firewall Management Center (FMC) Software and Cisco Security Cloud Control (SCC) Firewall Management Deserialization of Untrusted Data Vulnerability
Published Mar 4, 2026 · updated Jun 17, 2026 · Cisco Secure Firewall Management Center (FMC)
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.
Timeline
Detection, updates, and resolution for this record.
Mar 4, 2026 · Catalog
Detected
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 objec
Mar 19, 2026 · CISA KEV
Known exploited
Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
Mar 22, 2026 · CISA KEV
Remediation due
Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
Jun 17, 2026 · Catalog
Updated
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 objec
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 Mar 22, 2026
Affected
- cpe cisco/secure firewall management center6.4.0.13
- cpe cisco/secure firewall management center6.4.0.14
- cpe cisco/secure firewall management center6.4.0.15
- cpe cisco/secure firewall management center6.4.0.16
- cpe cisco/secure firewall management center6.4.0.17
- cpe cisco/secure firewall management center6.4.0.18
- cpe cisco/secure firewall management center7.0.0
- cpe cisco/secure firewall management center7.0.0.1
- vendor Cisco Secure Firewall Management Center (FMC)version unspecified
Sources
- CISA KEVCVE-2026-20131
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.
cisa.gov - CVE.orgCVE-2026-20131
Official CVE identifier
cve.org - FIRST EPSSCVE-2026-20131
30-day exploitation probability 43.2%
first.org - NIST NVDCVE-2026-20131
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 deserializat
nvd.nist.gov