CVE-2026-20131

CRITICALCISA KEV

10.0

Description

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.

CVE Details

CVSS v3.1 Score10.0

SeverityCRITICAL

CVSS VectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H

Attack VectorNETWORK

ComplexityLOW

Privileges RequiredNONE

User InteractionNONE

Published3/4/2026

Last Modified3/25/2026

Sourcekev

Honeypot Sightings0

CISA KEV

VendorCisco

ProductSecure Firewall Management Center (FMC)

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

KEV Date Added2026-03-19

Remediation Due Date2026-03-22

Ransomware UseKnown

Affected Products

cisco:secure_firewall_management_center

Weaknesses (CWE)

CWE-502

References

https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-fmc-rce-NKhnULJh(psirt@cisco.com)

https://aws.amazon.com/blogs/security/amazon-threat-intelligence-teams-identify-interlock-ransomware-campaign-targeting-enterprise-firewalls/(134c704f-9b21-4f2e-91b3-4a467353bcc0)

https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-20131(134c704f-9b21-4f2e-91b3-4a467353bcc0)

IOC Correlations

No correlations recorded

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