CVE-2026-20250
Cisco Secure Firewall Adaptive Security Appliance and Secure Firewall Threat Defense Software for Firepower 3100 and 4200 Series DTLS Denial of Service Vulnerability
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.
Weakness: CWE-772
Affected products
| Vendor | Product | Category | Matched by |
|---|---|---|---|
| Cisco | Cisco Adaptive Security Appliance (ASA) Check your version | Firewall / NGFW | cna-assigner |
| Cisco | Cisco Firepower Threat Defense (FTD) Check your version | Firewall / NGFW | cna-assigner |
Vendor-reported products (2)
- Cisco · Cisco Secure Firewall Adaptive Security Appliance (ASA) Software
- Cisco · Cisco Secure Firewall Threat Defense (FTD) Software
Vendor advisory
cisco-sa-asaftd-dtls-dos-Kp57HkyO
Cisco Secure Firewall Adaptive Security Appliance and Secure Firewall Threat Defense Software for Secure Firewall 3100 and 4200 Series DTLS Denial of Service Vulnerability
Cisco’s rating: High (advisory CVSS 8.6) · Published Sep 16, 2026 · updated Sep 18, 2026 (revision 1.1)
Bug IDs: CSCwq32085 , CSCws60947 , CSCwt11031
The vendor’s rating applies to the whole advisory and can differ from this CVE’s own CVSS severity. Where this comes from