CVE-2026-20135

A vulnerability in the TLS 1.3 implementation in Cisco Secure Firewall Threat Defense FTD Software could allow an unauthenticated, remote attacker to cause an affected device to reload unexpectedly, resulting in a denial of service DoS condition. This vulnerability is due to improper buffer...

CVE-2026-20135 Cisco Secure Firewall Threat Defense Software TLS 1.3 Denial of Service Vulnerability

A vulnerability in the TLS 1.3 implementation in Cisco Secure Firewall Threat Defense FTD Software could allow an unauthenticated, remote attacker to cause an affected device to reload unexpectedly, resulting in a denial of service DoS condition. This vulnerability is due to improper buffer...

EUVD-2026-81123

A vulnerability in the TLS 1.3 implementation in Cisco Secure Firewall Threat Defense FTD Software could allow an unauthenticated, remote attacker to cause an affected device to reload unexpectedly, resulting in a denial of service DoS condition. This vulnerability is due to improper buffer...

CVE-2026-20135

Cisco Secure Firewall Threat Defense (FTD) Software is vulnerable to a denial of service (DoS) via its TLS 1.3 implementation . The root cause is improper buffer management during TLS 1.3 connections. An unauthenticated, remote attacker can trigger a DoS by sending a crafted TLS 1.3 packet to a T...