---
id: CVE-2026-20250
title: >-
  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 dev…
summary: >-
  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 dev…
severity: high
cvss: 8.6
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H'
cwe:
  - CWE-772
vendor: Cisco
product: Cisco Secure Firewall Adaptive Security Appliance (ASA) Software
affected:
  - secure_firewall_adaptive_security_appliance_asa_software 9.23.1
  - secure_firewall_adaptive_security_appliance_asa_software 9.22.1.1
  - secure_firewall_adaptive_security_appliance_asa_software 9.22.1.3
  - secure_firewall_adaptive_security_appliance_asa_software 9.22.1.6
  - secure_firewall_adaptive_security_appliance_asa_software 9.22.2
  - secure_firewall_adaptive_security_appliance_asa_software 9.23.1.3
  - secure_firewall_adaptive_security_appliance_asa_software 9.22.2.4
  - secure_firewall_adaptive_security_appliance_asa_software 9.23.1.7
  - secure_firewall_adaptive_security_appliance_asa_software 9.22.2.9
  - secure_firewall_adaptive_security_appliance_asa_software 9.23.1.13
  - secure_firewall_adaptive_security_appliance_asa_software 9.22.2.13
  - secure_firewall_adaptive_security_appliance_asa_software 9.23.1.19
  - secure_firewall_adaptive_security_appliance_asa_software 9.22.2.14
  - secure_firewall_adaptive_security_appliance_asa_software 9.24.1
  - secure_firewall_adaptive_security_appliance_asa_software 9.23.1.22
  - secure_firewall_adaptive_security_appliance_asa_software 9.22.2.20
  - secure_firewall_adaptive_security_appliance_asa_software 9.23.1.26
  - secure_firewall_threat_defense_ftd_software 7.6.0
  - secure_firewall_threat_defense_ftd_software 7.7.0
  - secure_firewall_threat_defense_ftd_software 7.6.1
  - secure_firewall_threat_defense_ftd_software 7.6.2
  - secure_firewall_threat_defense_ftd_software 7.7.10
  - secure_firewall_threat_defense_ftd_software 7.7.11
  - secure_firewall_threat_defense_ftd_software 7.6.2.1
  - secure_firewall_threat_defense_ftd_software 7.7.10.1
  - secure_firewall_threat_defense_ftd_software 7.6.4
  - secure_firewall_threat_defense_ftd_software 10.0.0
published: '2026-09-16'
updated: '2026-09-18'
sourceUpdated: '2026-09-18T13:28:28.567'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-20250'
references:
  - url: >-
      https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-asaftd-dtls-dos-Kp57HkyO
    label: psirt@cisco.com
  - url: 'https://software.cisco.com'
tags:
  - nvd
  - cve.org
  - csaf
  - vendor-advisory
  - cisco
epss: 0.00549
epssPercentile: 0.43577
ssvc:
  exploitation: none
  automatable: 'yes'
  technicalImpact: partial
  timestamp: '2026-09-17T14:54:18.161264Z'
ingestedAt: '2026-09-16T16:37:52.182Z'
---

## Overview

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.

## Remediation

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

## Vendor advisories

- **cisco-sa-asaftd-dtls-dos-Kp57HkyO** · Cisco · affected: Cisco Secure Firewall 3100 Series, Cisco Secure Firewall 4200 Series · updated 2026-09-18 · [advisory](https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-asaftd-dtls-dos-Kp57HkyO)