CVE-2026-20250 PUBLISHED

Cisco Secure Firewall Adaptive Security Appliance and Secure Firewall Threat Defense Software for Firepower 3100 and 4200 Series DTLS Denial of Service Vulnerability

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

A vulnerability in Datagram TLS (DTLS) message handling of Cisco Secure Firewall Adaptive Security Appliance (ASA) Software and Cisco Secure Firewall Threat Defense (FTD) Software for Cisco Secure Firewall 3100 Series and 4200 Series devices could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device.

This vulnerability is due to improper resource management when processing certain DTLS messages. An attacker could exploit this vulnerability by sending a crafted stream of DTLS traffic to an affected device. A successful exploit could allow the attacker to cause the device to reload, resulting 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 Adaptive Security Appliance (ASA) Software
Versions Default: unknown
  • Version 9.23.1 is affected
  • Version 9.22.1.1 is affected
  • Version 9.22.1.3 is affected
  • Version 9.22.1.6 is affected
  • Version 9.22.2 is affected
  • Version 9.23.1.3 is affected
  • Version 9.22.2.4 is affected
  • Version 9.23.1.7 is affected
  • Version 9.22.2.9 is affected
  • Version 9.23.1.13 is affected
  • Version 9.22.2.13 is affected
  • Version 9.23.1.19 is affected
  • Version 9.22.2.14 is affected
  • Version 9.24.1 is affected
  • Version 9.23.1.22 is affected
  • Version 9.22.2.20 is affected
  • Version 9.23.1.26 is affected
Vendor Cisco
Product Cisco Secure Firewall Threat Defense (FTD) Software
Versions Default: unknown
  • Version 7.6.0 is affected
  • Version 7.7.0 is affected
  • Version 7.6.1 is affected
  • Version 7.6.2 is affected
  • Version 7.7.10 is affected
  • Version 7.7.11 is affected
  • Version 7.6.2.1 is affected
  • Version 7.7.10.1 is affected
  • Version 7.6.4 is affected
  • Version 10.0.0 is affected

Exploits

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

References

Problem Types

  • Missing Release of Resource after Effective Lifetime cwe