---
id: CVE-2026-20341
title: "A vulnerability in the sftunnel inter-device communication protocol of Cisco Secure FMC Software could allow an authenticated, remote attacker to obtain root privileges.\r\n\r\nThis vulnerability is due to unsecured deserialization of u…"
summary: "A vulnerability in the sftunnel inter-device communication protocol of Cisco Secure FMC Software could allow an authenticated, remote attacker to obtain root privileges.\r\n\r\nThis vulnerability is due to unsecured deserialization of u…"
severity: critical
cvss: 9.1
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H'
cwe:
  - CWE-502
vendor: Cisco
product: Cisco Secure Firewall Management Center (FMC)
affected:
  - secure_firewall_management_center_fmc 7.0.0
  - secure_firewall_management_center_fmc 7.0.0.1
  - secure_firewall_management_center_fmc 7.0.1
  - secure_firewall_management_center_fmc 7.0.1.1
  - secure_firewall_management_center_fmc 7.0.2
  - secure_firewall_management_center_fmc 7.2.0
  - secure_firewall_management_center_fmc 7.0.2.1
  - secure_firewall_management_center_fmc 7.0.3
  - secure_firewall_management_center_fmc 7.2.0.1
  - secure_firewall_management_center_fmc 7.0.4
  - secure_firewall_management_center_fmc 7.2.1
  - secure_firewall_management_center_fmc 7.0.5
  - secure_firewall_management_center_fmc 7.3.0
  - secure_firewall_management_center_fmc 7.2.2
  - secure_firewall_management_center_fmc 7.3.1
  - secure_firewall_management_center_fmc 7.2.3
  - secure_firewall_management_center_fmc 7.2.3.1
  - secure_firewall_management_center_fmc 7.2.4
  - secure_firewall_management_center_fmc 7.0.6
  - secure_firewall_management_center_fmc 7.2.4.1
  - secure_firewall_management_center_fmc 7.2.5
  - secure_firewall_management_center_fmc 7.3.1.1
  - secure_firewall_management_center_fmc 7.4.0
  - secure_firewall_management_center_fmc 7.0.6.1
  - secure_firewall_management_center_fmc 7.2.5.1
  - secure_firewall_management_center_fmc 7.4.1
  - secure_firewall_management_center_fmc 7.2.6
  - secure_firewall_management_center_fmc 7.4.1.1
  - secure_firewall_management_center_fmc 7.0.6.2
  - secure_firewall_management_center_fmc 7.2.7
  - secure_firewall_management_center_fmc 7.2.5.2
  - secure_firewall_management_center_fmc 7.3.1.2
  - secure_firewall_management_center_fmc 7.2.8
  - secure_firewall_management_center_fmc 7.6.0
  - secure_firewall_management_center_fmc 7.4.2
  - secure_firewall_management_center_fmc 7.2.8.1
  - secure_firewall_management_center_fmc 7.0.6.3
  - secure_firewall_management_center_fmc 7.4.2.1
  - secure_firewall_management_center_fmc 7.2.9
  - secure_firewall_management_center_fmc 7.0.7
  - secure_firewall_management_center_fmc 7.7.0
  - secure_firewall_management_center_fmc 7.4.2.2
  - secure_firewall_management_center_fmc 7.2.10
  - secure_firewall_management_center_fmc 7.6.1
  - secure_firewall_management_center_fmc 7.4.2.3
  - secure_firewall_management_center_fmc 7.0.8
  - secure_firewall_management_center_fmc 7.6.2
  - secure_firewall_management_center_fmc 7.7.10
  - secure_firewall_management_center_fmc 7.2.10.1
  - secure_firewall_management_center_fmc 7.0.8.1
published: '2026-09-16'
updated: '2026-09-18'
sourceUpdated: '2026-09-18T04:17:47.180'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-20341'
references:
  - url: >-
      https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-fmc-mulivulns-4PsnFwvx
    label: psirt@cisco.com
  - url: 'https://software.cisco.com'
tags:
  - nvd
  - cve.org
  - csaf
  - vendor-advisory
  - cisco
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: total
  timestamp: '2026-09-17T16:04:15.492734Z'
ingestedAt: '2026-09-16T16:37:52.201Z'
epss: 0.00445
epssPercentile: 0.38108
---

## Overview

A vulnerability in the sftunnel inter-device communication protocol of Cisco Secure FMC Software could allow an authenticated, remote attacker to obtain root privileges.

This vulnerability is due to unsecured deserialization of untrusted data over the sftunnel management connection. An attacker could exploit this vulnerability by sending crafted sftunnel remote procedure calls (RPCs). A successful exploit could allow the attacker to gain root privileges on a device that is running Cisco Secure FMC Software and its high-availability peer.
To exploit this vulnerability, the attacker must have valid administrative credentials on a managed Cisco FTD device.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.

## Vendor advisories

- **cisco-sa-fmc-mulivulns-4PsnFwvx** · Cisco · affected: Cisco Secure Firewall Management Center (FMC) Appliances · updated 2026-09-16 · [advisory](https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-fmc-mulivulns-4PsnFwvx)