---
title: "CVE-2026-20131: Cisco Secure Firewall Management Center… | CubePath"
description: "A vulnerability in the web-based management interface of Cisco Secure Firewall Management Center (FMC) Software could allow an unauthenticated, remote…"
language: en
source: https://cubepath.com/security/cve/CVE-2026-20131
---

# CVE-2026-20131: Cisco Secure Firewall Management Center… | CubePath

## 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.

Official description from the CVE record, published by cisco. Copyright © 1999-2026 The MITRE Corporation. See [/security/cve/legal](https://cubepath.com/security/cve/legal) for the CVE license. [View the record on cve.org](https://www.cve.org/CVERecord?id=CVE-2026-20131)

## Key data

### CVSS 3.1 Critical 10.0

Score published by cisco in the CVE record.

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

| Metric                 | Value   | What it means                                                                       |
| ---------------------- | ------- | ----------------------------------------------------------------------------------- |
| Attack vector          | Network | The vulnerable component can be reached over a network, possibly from the Internet. |
| Attack complexity      | Low     | No special conditions are needed. The attack can be repeated at will.               |
| Privileges required    | None    | No account or privileges are needed.                                                |
| User interaction       | None    | No action from any user is needed.                                                  |
| Scope                  | Changed | The impact can reach other components beyond the vulnerable one.                    |
| Confidentiality impact | High    | Serious or total effect on the secrecy of data.                                     |
| Integrity impact       | High    | Serious or total effect on the trustworthiness of data.                             |
| Availability impact    | High    | Serious or total effect on availability.                                            |

CVSS is owned and managed by FIRST.Org, Inc. (FIRST) and is used by permission. Each CVSS score on this site is shown together with its vector string, as published in the CVE record by the source named next to it. Learn more at [first.org/cvss](https://www.first.org/cvss/) .

### EPSS

Exploit Prediction Scoring System by FIRST: an estimate of the probability that exploitation activity will be observed in the next 30 days.

Score

0.44431 (44.4% probability)

Percentile

98.8%

Scores of

Nov 10, 2026

Model

v2026.06.15

### CISA Known Exploited Vulnerabilities

This CVE is listed in the CISA KEV catalog.

Name in the catalog

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

Added to the catalog

Mar 19, 2026

Federal due date

Mar 22, 2026

Ransomware campaigns

Known use

### CISA assessment as of Mar 4, 2026

Stakeholder-Specific Vulnerability Categorization (SSVC) decision points added by CISA.

Exploitation

Recorded by CISA as active

Automatable

yes

Technical impact

total

### Weakness (CWE)

CWE catalog version 5.0.

CWE names: Copyright © 2006-2026, The MITRE Corporation. See [/security/cve/legal](https://cubepath.com/security/cve/legal) for the CWE license.

- [CWE-502](https://cwe.mitre.org/data/definitions/502.html) Deserialization of Untrusted Data

## Affected products

Products listed in the CVE record, as the CNA published them.

- Cisco Secure Firewall Management Center (FMC)

  - affected: 7.0.0
  - affected: 7.0.0.1
  - affected: 7.0.1
  - affected: 7.1.0
  - affected: 6.4.0.13
  - affected: 7.0.1.1
  - affected: 6.4.0.14
  - affected: 7.1.0.1
  - affected: 7.0.2
  - affected: 6.4.0.15
  - affected: 7.2.0
  - affected: 7.0.2.1
  - affected: 7.0.3
  - affected: 7.1.0.2
  - affected: 7.2.0.1
  - affected: 7.0.4
  - affected: 7.2.1
  - affected: 7.0.5
  - affected: 6.4.0.16
  - affected: 7.3.0
  - affected: 7.2.2
  - affected: 7.3.1
  - affected: 7.2.3
  - affected: 7.1.0.3
  - affected: 7.2.3.1
  - and 45 more

## References

Links listed in the CVE record. They lead to other sites, which CubePath does not control.

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

## Timeline

1. ID reserved Oct 8, 2025
2. Record published Mar 4, 2026
3. Added to CISA KEV Mar 19, 2026
4. Record last updated Aug 14, 2026

## Look up another CVE

## About CubePath

CubePath is a cloud provider with data centers in Europe and the United States. It offers VPS, bare metal servers and DDoS protection.

[Cloud VPS](https://cubepath.com/vps) [DDoS protection](https://cubepath.com/ddos-protection)

Data from the CVE Program (MITRE), CISA KEV and FIRST EPSS. CVSS is owned by FIRST and used by permission. Not affiliated with or endorsed by MITRE, CISA or FIRST. Data as of Nov 10, 2026, 19:13 UTC. [Sources and licenses](https://cubepath.com/security/cve/legal)