CVE-2026-20250: cisco cisco secure firewall adaptive security appliance (asa) software

Vulnerability summary

CVE-2026-20250 is a high (CVSS 8.6) vulnerability in cisco cisco secure firewall adaptive security appliance (asa) software. EPSS estimates a 0.55% chance of exploitation in the next 30 days, higher than 45.1% of scored vulnerabilities.

Timeline

1. 16-09-2026
   PublishedVulnerability first disclosed.
2. 18-09-2026
   Last modifiedVulnerability information updated.

Description

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.

• CWE-772Missing Release of Resource after Effective LifetimeThe product does not release a resource after its effective lifetime has ended, i.e., after the resource is no longer needed.