Vulnerability · CVE-2026-20324
Cisco Secure Firewall Management Center Software sftunnel Root Arbitrary Code Execution Vulnerability
Published Sep 16, 2026 · Cisco · evidence confidence high
A vulnerability in the sftunnel inter-device communication protocol of Cisco Secure Firewall Management Center (FMC) Software could allow an authenticated, remote attacker to execute arbitrary commands as root . This vulnerability exists because a registered sftunnel peer has incorrect permissions to write an arbitrary file to any location on the device. An attacker could exploit this vulnerability by hijacking the sftunnel communication connection or being a valid registered sftunnel peer and sending an sftunnel command to write a malicious file to the disk of an affected de
Grounded briefings
Catalog interpretations for three audiences. Each brief cites ingested metadata and the original advisories below. They are not independent research and they do not invent exploit steps.
Executive
CVE-2026-20324 is a unknown public vulnerability record for Cisco. It is not currently listed in the CISA Known Exploited catalog. Check the linked vendor or CERT advisories for patch status. This summary is a catalog interpretation of the ingested metadata and cites the original advisories below.
System administrator
Identify whether Cisco is in your estate, then compare installed versions with the affected ranges. Affected version ranges have not been ingested yet. Check the linked vendor or CERT advisories for patch status. Prefer the vendor or distribution advisory linked in Sources before changing production systems. This is a catalog interpretation, not a runbook.
Security analyst
Signals on file: EPSS 0.4%. It is not currently listed in the CISA Known Exploited catalog. Sources contributing to this record: cisco, epss. Public exploit references, when present, are outbound links only and are not proof of active exploitation. This is a catalog interpretation of stored metadata.
Exploitation and remediation
Exploitation evidence
Not listed as known exploited in CISA KEV. Not in CISA KEV or VulnCheck KEV.
Patch and remediation
No required-action text is stored yet. Use the vendor or CERT links in Sources for patch availability.
Safe detection guidance
Compare installed versions with the affected ranges below and verify the advisory from the original publisher. This site stores metadata and outbound links only; it does not ship exploit code or proof-of-concept payloads.
Technology hubs
Code
The project this record applies to. Exploit listings stay in References.
No public source repository is identified for this product.
Timeline
Detection, updates, and resolution for this record.
Sep 16, 2026 · Cisco Security Advisories
Detected
A vulnerability in the sftunnel inter-device communication protocol of Cisco Secure Firewall Management Center (FMC) Software could allow an authenticated, remote attacker to execute arbitrary commands as root . This vulnerability exists because a registered sftunnel peer has incorrect permissions to write an arbitrary file to any location on the device. An attacker could exploit this vulnerabilit
Sources
- Cisco Security AdvisoriesVendor advisoryCVE-2026-20324
A vulnerability in the sftunnel inter-device communication protocol of Cisco Secure Firewall Management Center (FMC) Software could allow an authenticated, remote attacker to execute arbitrary commands as root . This vulnerability exists because a registered sftunnel peer has inc
sec.cloudapps.cisco.com - FIRST EPSSExploitation probabilityCVE-2026-20324
30-day exploitation probability 0.4%
first.org