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

Cisco Secure Firewall Management Center (FMC)

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. Added to CISA KEV on 2026-03-19 (federal deadline 2026-03-22).

First seen: 19 Mar 2026
Last update: 19 Mar 2026, 12:00 UTC
Identifiers: CVE-2026-20131
Source: CISA KEV
On the menu as: Java
VPN & firewalls

Check this repository for exposure to one security incident from pwned.coffee. Report first, change nothing until I say so.

## Cisco Secure Firewall Management Center (FMC) Software and Cisco Security Cloud Control (SCC) Firewall Management Deserialization of Untrusted Data Vulnerability
Severity: critical, exploited in the wild. Patch status: patched.
Affected: Cisco Secure Firewall Management Center (FMC)
Ids: CVE-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. Added to CISA KEV on 2026-03-19 (federal deadline 2026-03-22).

## Steps
1. This touches infrastructure (vpn-edge). Look in terraform, ansible, cloud-init, Dockerfiles and docs for the product and version we run. If it isn't in the repo, say so and list what a human should check on the box.

## Report
A table: file, product or package, version in use, affected yes/no, exact fix. Then anything a human has to check outside the repo.

If you have the pwned.coffee MCP server (https://pwned.coffee/mcp), call lookup_cve("CVE-2026-20131") for the latest, and check_repo with this repo's lockfiles, Dockerfiles and workflows for a full receipt.
Sources: https://nvd.nist.gov/vuln/detail/CVE-2026-20131 https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-fmc-rce-NKhnULJh
https://pwned.coffee/i/cisco-secure-firewall-management-center-fmc-software-and-cve-2026-20131

Sources

Totalone very hot coffee