CVE-2026-20105

High

Description

A vulnerability in the Remote Access SSL VPN functionality of Cisco Secure Firewall Adaptive Security Appliance (ASA) Software and Secure Firewall Threat Defense (FTD) Software could allow an authenticated, remote attacker with a valid VPN connection to exhaust device memory resulting in a denial of service (DoS) condition.This does not affect the management or MUS interfaces. This vulnerability is due to trusting user input without validation. An attacker could exploit this vulnerability by sending crafted packets to the Remote Access SSL VPN server. A successful exploit could allow the attacker to cause the device to reload, resulting in a DoS condition.

SeverityHigh
CVSS7.7
Exploit probability—
ProductCisco Adaptive Security Appliance Software
PublishedMar 4, 2026
First seenMar 4, 2026
Weakness typeCWE-401CWE-401

How to fix

Update
  • cisco adaptive_security_appliance_software9.16.4.85, 9.18.4.66, 9.20.4, 9.22.2.4, 9.23.1.7 or later
  • cisco secure_firewall_threat_defense7.0.9, 7.2.11, 7.4.3, 7.6.4, 7.7.11 or later

Affected products

ProductAffected versionsFixed in
cisco adaptive_security_appliance_software9.12.1 ≤ v < 9.16.4.85, 9.17.1 ≤ v < 9.18.4.66, 9.19.1 ≤ v < 9.20.4, 9.22.1.1 ≤ v < 9.22.2.4, 9.23.1 ≤ v < 9.23.1.79.16.4.85, 9.18.4.66, 9.20.4, 9.22.2.4, 9.23.1.7
cisco secure_firewall_threat_defense6.4.0 ≤ v < 7.0.9, 7.1.0 ≤ v < 7.2.11, 7.3.0 ≤ v < 7.4.3, 7.6.0 ≤ v < 7.6.4, 7.7.0 ≤ v < 7.7.117.0.9, 7.2.11, 7.4.3, 7.6.4, 7.7.11

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