# CVE-2026-20131: Cisco Secure Firewall Management Center Software Remote Code Execution Vulnerability

> CVE-2026-20131: Cisco Secure Firewall Management Center Software Remote Code Execution Vulnerability. CVSS 10.0 (CVSS 3.1), in CISA KEV.

Canonical: https://rewindex.com/cve/CVE-2026-20131
Last updated: 2026-08-14T03:55:24Z

- Published: 2026-03-04 17:17 UTC · Updated: 2026-08-14 03:55 UTC · Assigner: cisco
- CVSS: 10.0 (CVSS 3.1) · Severity: Critical · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
- EPSS: 43.2%, 99th percentile (scored 2026-10-25)
- CISA KEV: yes, added 2026-03-19, federal due date 2026-03-22, ransomware use: Known
- CWE: CWE-502

## 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.

## CISA 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.

## Affected vendors and products

- Cisco: Cisco Secure Firewall Management Center (FMC)

## References

- [CVE record on cve.org](https://www.cve.org/CVERecord?id=CVE-2026-20131)
- [NVD entry](https://nvd.nist.gov/vuln/detail/CVE-2026-20131)
- [https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-fmc-rce-NKhnULJh](https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-fmc-rce-NKhnULJh)

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_Sources: CVE records from the CVE Program (cve.org). CVE® is a registered trademark of The MITRE Corporation. (https://www.cve.org/) This product uses data from the NVD API but is not endorsed or certified by the NVD. (https://nvd.nist.gov/) Known Exploited Vulnerabilities catalog from CISA. (https://www.cisa.gov/known-exploited-vulnerabilities-catalog) EPSS scores from FIRST (Exploit Prediction Scoring System). (https://www.first.org/epss/)_


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Canonical: https://rewindex.com/cve/CVE-2026-20131 · Markdown: https://rewindex.com/cve/CVE-2026-20131.md · JSON: https://rewindex.com/api/v1/cves/CVE-2026-20131 · Data licensed CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/) · Generated 2026-10-26T04:04:01.906Z