CVE-2026-20101: Cisco Adaptive Security Appliance Software

High severity, CVSS 8.6. EPSS: 0.4% chance of exploitation in the next 30 days.

A vulnerability in the SAML 2.0 single sign-on (SSO) feature of Cisco Secure Firewall ASA Software and Secure FTD Software could allow an unauthenticated, remote attacker to cause the device to reload unexpectedly, resulting in a DoS condition. This vulnerability is due to insufficient error checking when processing SAML messages. An attacker could exploit this vulnerability by sending crafted SAML messages to the SAML service. A successful exploit could allow the attacker to cause the device to reload, resulting in a DoS condition.

Affected products

• Cisco Adaptive Security Appliance Software: from 9.12.1, before 9.16.4.85 (fixed in 9.16.4.85); from 9.17.1, before 9.18.4.66 (fixed in 9.18.4.66); from 9.19.1, before 9.20.4 (fixed in 9.20.4); from 9.22.1.1, before 9.22.2.4 (fixed in 9.22.2.4); from 9.23.1, before 9.23.1.7 (fixed in 9.23.1.7)
• Cisco Secure Firewall Threat Defense: from 6.4.0, before 7.0.9 (fixed in 7.0.9); from 7.1.0, before 7.2.11 (fixed in 7.2.11); from 7.3.0, before 7.4.3 (fixed in 7.4.3); from 7.6.0, before 7.6.4 (fixed in 7.6.4); from 7.7.0, before 7.7.11 (fixed in 7.7.11)

Published 2026-03-04. Last modified 2026-08-11.