CVE-2026-20295 PUBLISHED

Cisco Secure Firewall Management Center and Secure Firewall Threat Defense Software sftunnel Memory Exhaustion Denial of Service Vulnerability

Assigner: cisco
Reserved: 08.10.2025 Published: 16.09.2026 Updated: 16.09.2026

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

CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H
CVSS Score: 8.6

Product Status

Vendor Cisco
Product Cisco Secure Firewall Management Center (FMC)
Versions Default: unknown
  • Version 7.0.0 is affected
  • Version 7.0.0.1 is affected
  • Version 7.0.1 is affected
  • Version 7.0.1.1 is affected
  • Version 7.0.2 is affected
  • Version 7.2.0 is affected
  • Version 7.0.2.1 is affected
  • Version 7.0.3 is affected
  • Version 7.2.0.1 is affected
  • Version 7.0.4 is affected
  • Version 7.2.1 is affected
  • Version 7.0.5 is affected
  • Version 7.3.0 is affected
  • Version 7.2.2 is affected
  • Version 7.3.1 is affected
  • Version 7.2.3 is affected
  • Version 7.2.3.1 is affected
  • Version 7.2.4 is affected
  • Version 7.0.6 is affected
  • Version 7.2.4.1 is affected
  • Version 7.2.5 is affected
  • Version 7.3.1.1 is affected
  • Version 7.4.0 is affected
  • Version 7.0.6.1 is affected
  • Version 7.2.5.1 is affected
  • Version 7.4.1 is affected
  • Version 7.2.6 is affected
  • Version 7.4.1.1 is affected
  • Version 7.0.6.2 is affected
  • Version 7.2.7 is affected
  • Version 7.2.5.2 is affected
  • Version 7.3.1.2 is affected
  • Version 7.2.8 is affected
  • Version 7.6.0 is affected
  • Version 7.4.2 is affected
  • Version 7.2.8.1 is affected
  • Version 7.0.6.3 is affected
  • Version 7.4.2.1 is affected
  • Version 7.2.9 is affected
  • Version 7.0.7 is affected
  • Version 7.7.0 is affected
  • Version 7.4.2.2 is affected
  • Version 7.2.10 is affected
  • Version 7.6.1 is affected
  • Version 7.4.2.3 is affected
  • Version 7.0.8 is affected
  • Version 7.6.2 is affected
  • Version 7.7.10 is affected
  • Version 7.2.10.1 is affected
  • Version 7.0.8.1 is affected
  • Version 7.6.2.1 is affected
  • Version 7.2.10.2 is affected
  • Version 7.7.10.1 is affected
  • Version 7.4.2.4 is affected
  • Version 7.4.3 is affected
  • Version 7.6.3 is affected
  • Version 7.7.11 is affected
  • Version 7.6.4 is affected
  • Version 10.0.0 is affected
  • Version 7.4.4 is affected
  • Version 7.4.5 is affected
  • Version 7.0.9 is affected
  • Version 7.2.11 is affected
  • Version 7.7.12 is affected
  • Version 7.6.5 is affected
  • Version 7.4.6 is affected
  • Version 10.0.1 is affected
Vendor Cisco
Product Cisco Secure Firewall Threat Defense (FTD) Software
Versions Default: unknown
  • Version 7.0.0 is affected
  • Version 7.0.0.1 is affected
  • Version 7.0.1 is affected
  • Version 7.0.1.1 is affected
  • Version 7.0.2 is affected
  • Version 7.2.0 is affected
  • Version 7.0.2.1 is affected
  • Version 7.0.3 is affected
  • Version 7.2.0.1 is affected
  • Version 7.0.4 is affected
  • Version 7.2.1 is affected
  • Version 7.0.5 is affected
  • Version 7.3.0 is affected
  • Version 7.2.2 is affected
  • Version 7.2.3 is affected
  • Version 7.3.1 is affected
  • Version 7.2.4 is affected
  • Version 7.0.6 is affected
  • Version 7.2.5 is affected
  • Version 7.2.4.1 is affected
  • Version 7.3.1.1 is affected
  • Version 7.4.0 is affected
  • Version 7.0.6.1 is affected
  • Version 7.2.5.1 is affected
  • Version 7.4.1 is affected
  • Version 7.2.6 is affected
  • Version 7.0.6.2 is affected
  • Version 7.4.1.1 is affected
  • Version 7.2.7 is affected
  • Version 7.2.5.2 is affected
  • Version 7.3.1.2 is affected
  • Version 7.2.8 is affected
  • Version 7.6.0 is affected
  • Version 7.4.2 is affected
  • Version 7.2.8.1 is affected
  • Version 7.0.6.3 is affected
  • Version 7.4.2.1 is affected
  • Version 7.2.9 is affected
  • Version 7.0.7 is affected
  • Version 7.7.0 is affected
  • Version 7.4.2.2 is affected
  • Version 7.2.10 is affected
  • Version 7.6.1 is affected
  • Version 7.4.2.3 is affected
  • Version 7.0.8 is affected
  • Version 7.6.2 is affected
  • Version 7.7.10 is affected
  • Version 7.7.11 is affected
  • Version 7.0.8.1 is affected
  • Version 7.6.2.1 is affected
  • Version 7.7.10.1 is affected
  • Version 7.4.2.4 is affected
  • Version 7.2.10.2 is affected
  • Version 7.4.3 is affected
  • Version 7.6.4 is affected
  • Version 10.0.0 is affected
  • Version 7.4.4 is affected
  • Version 7.0.9 is affected
  • Version 7.2.11 is affected

Exploits

The Cisco Product Security Incident Response Team (PSIRT) is not aware of any public announcements or malicious use of the vulnerabilities that are described in this advisory.

References

Problem Types

  • Memory Allocation with Excessive Size Value cwe