CVE-2026-20349

A vulnerability in the Remote Access SSL VPN service for Cisco Secure Firewall Adaptive Security Appliance (ASA) Software and Cisco Secure Firewall Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to cause the device to reload unexpectedly, resulting in a denial of service (DoS) condition.  This vulnerability is due to insufficient error checking when processing HTTP requests. An attacker could exploit this vulnerability by sending a crafted HTTP request to the Remote Access SSL VPN service on an affected device. A successful exploit could allow the attacker to cause the affected device to reload, resulting in a DoS condition.

Affected products

Secure Firewall Asa, Secure Firewall Ftd

Cisco Adaptive Security Appliance Software

= 9.16.1, 9.16.1.28, 9.16.2, 9.16.2.3, 9.16.2.7, 9.16.2.11, 9.16.2.13, 9.16.2.14, 9.16.3, 9.16.3.3, 9.16.3.14, 9.16.3.15, 9.16.3.19, 9.16.3.23, 9.16.4, 9.16.4.9, 9.16.4.14, 9.16.4.19, 9.16.4.27, 9.16.4.38, 9.16.4.39, 9.16.4.42, 9.16.4.48, 9.16.4.55, 9.16.4.57, 9.16.4.61, 9.16.4.62, 9.16.4.67, 9.16.4.70, 9.16.4.71, 9.16.4.76, 9.16.4.82, 9.16.4.84, 9.16.4.85, 9.16.4.89, 9.16.4.92, 9.18.1, 9.18.1.3, 9.18.2, 9.18.2.5

CVSS 3.1

8.6 HIGH

EPSS

1.0% (59th percentile)

Weakness

CWE-244

NVD status

Analyzed

Published

2026-08-11