A vulnerability in the sftunnel inter-device communication protocol of Cisco Secure FMC Software and Cisco Secure FTD Software could allow an unauthenticated, remote attacker to exhaust the available memory of an affected device. This vulnerability is due to improper management of memory resources during sftunnel TLS connection setup. An attacker could exploit this vulnerability by sending crafted sftunnel TLS frames to an affected device during the connection setup. A successful exploit could allow the attacker to exhaust the available memory on the affected device, which could result in a DoS condition.

Metrics

No CVSS v4.0

Attack Vector Network

Attack Complexity Low

Privileges Required None

Scope Changed

Confidentiality Impact None

Integrity Impact None

Availability Impact High

User Interaction None

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

Exploitation none

Automatable yes

Technical Impact partial

Affected Vendors & Products

Vendors Products
Cisco
  • Secure Firewall Management Center
  • Secure Firewall Threat Defense

No data.

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References
Link Providers
https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-fmcftd-sftun-multivulns-WGVHOrN3 cve-icon cve-icon
History

Sat, 19 Sep 2026 23:00:00 +0000

Type Values Removed Values Added
First Time appeared Cisco
Cisco secure Firewall Management Center
Cisco secure Firewall Threat Defense
Vendors & Products Cisco
Cisco secure Firewall Management Center
Cisco secure Firewall Threat Defense

Thu, 17 Sep 2026 14:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Wed, 16 Sep 2026 20:30:00 +0000

Type Values Removed Values Added
Description A vulnerability in the sftunnel inter-device communication protocol of Cisco Secure FMC Software and Cisco Secure FTD Software could allow an unauthenticated, remote attacker to exhaust the available memory of an affected device. This vulnerability is due to improper management of memory resources during sftunnel TLS connection setup. An attacker could exploit this vulnerability by sending crafted sftunnel TLS frames to an affected device during the connection setup. A successful exploit could allow the attacker to exhaust the available memory on the affected device, which could result in a DoS condition.
Title Cisco Secure Firewall Management Center and Secure Firewall Threat Defense Software sftunnel Memory Exhaustion Denial of Service Vulnerability
Weaknesses CWE-789
References
Metrics cvssV3_1

{'score': 8.6, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H'}
cve-icon MITRE

Status: PUBLISHED

Assigner: cisco

Published: 2026-09-16T20:09:56.746Z

Updated: 2026-09-17T13:40:57.982Z

Reserved: 2025-10-08T11:59:15.405Z

Link: CVE-2026-20295

cve-icon Vulnrichment

Updated: 2026-09-17T13:36:18.091Z

cve-icon NVD

Status : Awaiting Analysis

Published: 2026-09-16T21:17:09.740

Modified: 2026-09-18T13:28:28.567

Link: CVE-2026-20295

cve-icon Redhat

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