CVE-2026-20105: High severity Cisco Secure Firewall Adaptive Security Appliance vulnerability

Published Mar 4, 2026
·
Updated

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.

Affected Software

12 affected components
Cisco Secure Firewall Adaptive Security Appliance
Cisco Secure Firewall Threat Defense
Cisco Adaptive Security Appliance Software>=9.12.1<9.16.4.85
Cisco Adaptive Security Appliance Software>=9.17.1<9.18.4.66
Cisco Adaptive Security Appliance Software>=9.19.1<9.20.4
Cisco Adaptive Security Appliance Software>=9.22.1.1<9.22.2.4
Cisco Adaptive Security Appliance Software>=9.23.1<9.23.1.7
Cisco Secure Firewall Threat Defense>=6.4.0<7.0.9
Cisco Secure Firewall Threat Defense>=7.1.0<7.2.11
Cisco Secure Firewall Threat Defense>=7.3.0<7.4.3
Cisco Secure Firewall Threat Defense>=7.6.0<7.6.4
Cisco Secure Firewall Threat Defense>=7.7.0<7.7.11

Event History

Mar 4, 2026
CVE Published
via MITRE·05:19 PM
Data Sourced
via MITRE·05:19 PM
DescriptionSeverityWeakness
Data Sourced
via NVD·06:16 PM
DescriptionSeverityWeaknessAffected Software
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Frequently Asked Questions

1

What is the severity of CVE-2026-20105?

CVE-2026-20105 is rated as a critical severity vulnerability that can lead to a denial of service due to memory exhaustion.

2

How do I fix CVE-2026-20105?

To mitigate CVE-2026-20105, upgrade Cisco Secure Firewall Adaptive Security Appliance and Secure Firewall Threat Defense software to the latest patched version.

3

Who is affected by CVE-2026-20105?

CVE-2026-20105 affects users of Cisco Secure Firewall Adaptive Security Appliance and Secure Firewall Threat Defense appliances with enabled SSL VPN functionality.

4

What type of attack does CVE-2026-20105 allow?

CVE-2026-20105 allows an authenticated remote attacker to exhaust device memory, resulting in denial of service.

5

Can CVE-2026-20105 be exploited without authentication?

No, CVE-2026-20105 requires an authenticated user with a valid VPN connection to exploit the vulnerability.

Contact

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