CVE-2026-20100: High severity Cisco Secure Firewall Adaptive Security Appliance (ASA) Software vulnerability

Published Mar 4, 2026
·
Updated

A vulnerability in the LUA interperter of the Remote Access SSL VPN feature 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 cause the device to reload unexpectedly, 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 in the LUA interprerter. An attacker could exploit this vulnerability by sending crafted HTTP 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

224 affected components
Cisco Secure Firewall Adaptive Security Appliance (ASA) Software
Cisco Secure Firewall Threat Defense (FTD) Software
Cisco Adaptive Security Appliance Software=9.12.1
Cisco Adaptive Security Appliance Software=9.12.1.2
Cisco Adaptive Security Appliance Software=9.12.1.3
Cisco Adaptive Security Appliance Software=9.12.2
Cisco Adaptive Security Appliance Software=9.12.2.1
Cisco Adaptive Security Appliance Software=9.12.2.4
Cisco Adaptive Security Appliance Software=9.12.2.5
Cisco Adaptive Security Appliance Software=9.12.2.9
Cisco Adaptive Security Appliance Software=9.12.3
Cisco Adaptive Security Appliance Software=9.12.3.2
Cisco Adaptive Security Appliance Software=9.12.3.7
Cisco Adaptive Security Appliance Software=9.12.3.9
Cisco Adaptive Security Appliance Software=9.12.3.12
Cisco Adaptive Security Appliance Software=9.12.4
Cisco Adaptive Security Appliance Software=9.12.4.2
Cisco Adaptive Security Appliance Software=9.12.4.4
Cisco Adaptive Security Appliance Software=9.12.4.7
Cisco Adaptive Security Appliance Software=9.12.4.8
Cisco Adaptive Security Appliance Software=9.12.4.10
Cisco Adaptive Security Appliance Software=9.12.4.13
Cisco Adaptive Security Appliance Software=9.12.4.18
Cisco Adaptive Security Appliance Software=9.12.4.24
Cisco Adaptive Security Appliance Software=9.12.4.26
Cisco Adaptive Security Appliance Software=9.12.4.29
Cisco Adaptive Security Appliance Software=9.12.4.30
Cisco Adaptive Security Appliance Software=9.12.4.35
Cisco Adaptive Security Appliance Software=9.12.4.37
Cisco Adaptive Security Appliance Software=9.12.4.38
Cisco Adaptive Security Appliance Software=9.12.4.39
Cisco Adaptive Security Appliance Software=9.12.4.40
Cisco Adaptive Security Appliance Software=9.12.4.41
Cisco Adaptive Security Appliance Software=9.12.4.47
Cisco Adaptive Security Appliance Software=9.12.4.48
Cisco Adaptive Security Appliance Software=9.12.4.50
Cisco Adaptive Security Appliance Software=9.12.4.52
Cisco Adaptive Security Appliance Software=9.12.4.54
Cisco Adaptive Security Appliance Software=9.12.4.55
Cisco Adaptive Security Appliance Software=9.12.4.56
Cisco Adaptive Security Appliance Software=9.12.4.58
Cisco Adaptive Security Appliance Software=9.12.4.62
Cisco Adaptive Security Appliance Software=9.12.4.65
Cisco Adaptive Security Appliance Software=9.12.4.67
Cisco Adaptive Security Appliance Software=9.16.1
Cisco Adaptive Security Appliance Software=9.16.1.28
Cisco Adaptive Security Appliance Software=9.16.2
Cisco Adaptive Security Appliance Software=9.16.2.3
Cisco Adaptive Security Appliance Software=9.16.2.7
Cisco Adaptive Security Appliance Software=9.16.2.11
Cisco Adaptive Security Appliance Software=9.16.2.13
Cisco Adaptive Security Appliance Software=9.16.2.14
Cisco Adaptive Security Appliance Software=9.16.3
Cisco Adaptive Security Appliance Software=9.16.3.3
Cisco Adaptive Security Appliance Software=9.16.3.14
Cisco Adaptive Security Appliance Software=9.16.3.15
Cisco Adaptive Security Appliance Software=9.16.3.19
Cisco Adaptive Security Appliance Software=9.16.3.23
Cisco Adaptive Security Appliance Software=9.16.4
Cisco Adaptive Security Appliance Software=9.16.4.9
Cisco Adaptive Security Appliance Software=9.16.4.14
Cisco Adaptive Security Appliance Software=9.16.4.19
Cisco Adaptive Security Appliance Software=9.16.4.27
Cisco Adaptive Security Appliance Software=9.16.4.38
Cisco Adaptive Security Appliance Software=9.16.4.39
Cisco Adaptive Security Appliance Software=9.16.4.42
Cisco Adaptive Security Appliance Software=9.16.4.48
Cisco Adaptive Security Appliance Software=9.16.4.55
Cisco Adaptive Security Appliance Software=9.16.4.57
Cisco Adaptive Security Appliance Software=9.16.4.61
Cisco Adaptive Security Appliance Software=9.16.4.62
Cisco Adaptive Security Appliance Software=9.16.4.67
Cisco Adaptive Security Appliance Software=9.16.4.70
Cisco Adaptive Security Appliance Software=9.16.4.71
Cisco Adaptive Security Appliance Software=9.16.4.76
Cisco Adaptive Security Appliance Software=9.16.4.82
Cisco Adaptive Security Appliance Software=9.16.4.84
Cisco Adaptive Security Appliance Software=9.17.1
Cisco Adaptive Security Appliance Software=9.17.1.7
Cisco Adaptive Security Appliance Software=9.17.1.9
Cisco Adaptive Security Appliance Software=9.17.1.10
Cisco Adaptive Security Appliance Software=9.17.1.11
Cisco Adaptive Security Appliance Software=9.17.1.13
Cisco Adaptive Security Appliance Software=9.17.1.15
Cisco Adaptive Security Appliance Software=9.17.1.20
Cisco Adaptive Security Appliance Software=9.17.1.30
Cisco Adaptive Security Appliance Software=9.17.1.33
Cisco Adaptive Security Appliance Software=9.17.1.39
Cisco Adaptive Security Appliance Software=9.17.1.45
Cisco Adaptive Security Appliance Software=9.17.1.46
Cisco Adaptive Security Appliance Software=9.18.1
Cisco Adaptive Security Appliance Software=9.18.1.3
Cisco Adaptive Security Appliance Software=9.18.2
Cisco Adaptive Security Appliance Software=9.18.2.5
Cisco Adaptive Security Appliance Software=9.18.2.7
Cisco Adaptive Security Appliance Software=9.18.2.8
Cisco Adaptive Security Appliance Software=9.18.3
Cisco Adaptive Security Appliance Software=9.18.3.39
Cisco Adaptive Security Appliance Software=9.18.3.46
Cisco Adaptive Security Appliance Software=9.18.3.53
Cisco Adaptive Security Appliance Software=9.18.3.55
Cisco Adaptive Security Appliance Software=9.18.3.56
Cisco Adaptive Security Appliance Software=9.18.4
Cisco Adaptive Security Appliance Software=9.18.4.5
Cisco Adaptive Security Appliance Software=9.18.4.8
Cisco Adaptive Security Appliance Software=9.18.4.22
Cisco Adaptive Security Appliance Software=9.18.4.24
Cisco Adaptive Security Appliance Software=9.18.4.29
Cisco Adaptive Security Appliance Software=9.18.4.34
Cisco Adaptive Security Appliance Software=9.18.4.40
Cisco Adaptive Security Appliance Software=9.18.4.47
Cisco Adaptive Security Appliance Software=9.18.4.50
Cisco Adaptive Security Appliance Software=9.18.4.52
Cisco Adaptive Security Appliance Software=9.18.4.53
Cisco Adaptive Security Appliance Software=9.18.4.57
Cisco Adaptive Security Appliance Software=9.19.1
Cisco Adaptive Security Appliance Software=9.19.1.5
Cisco Adaptive Security Appliance Software=9.19.1.9
Cisco Adaptive Security Appliance Software=9.19.1.12
Cisco Adaptive Security Appliance Software=9.19.1.18
Cisco Adaptive Security Appliance Software=9.19.1.22
Cisco Adaptive Security Appliance Software=9.19.1.24
Cisco Adaptive Security Appliance Software=9.19.1.27
Cisco Adaptive Security Appliance Software=9.19.1.28
Cisco Adaptive Security Appliance Software=9.19.1.31
Cisco Adaptive Security Appliance Software=9.19.1.37
Cisco Adaptive Security Appliance Software=9.19.1.38
Cisco Adaptive Security Appliance Software=9.19.1.42
Cisco Adaptive Security Appliance Software=9.20.1
Cisco Adaptive Security Appliance Software=9.20.1.5
Cisco Adaptive Security Appliance Software=9.20.2
Cisco Adaptive Security Appliance Software=9.20.2.10
Cisco Adaptive Security Appliance Software=9.20.2.21
Cisco Adaptive Security Appliance Software=9.20.2.22
Cisco Adaptive Security Appliance Software=9.20.3
Cisco Adaptive Security Appliance Software=9.20.3.4
Cisco Adaptive Security Appliance Software=9.20.3.7
Cisco Adaptive Security Appliance Software=9.20.3.9
Cisco Adaptive Security Appliance Software=9.20.3.10
Cisco Adaptive Security Appliance Software=9.20.3.13
Cisco Adaptive Security Appliance Software=9.20.3.16
Cisco Adaptive Security Appliance Software=9.20.3.20
Cisco Adaptive Security Appliance Software=9.22.1.1
Cisco Adaptive Security Appliance Software=9.22.1.2
Cisco Adaptive Security Appliance Software=9.22.1.3
Cisco Adaptive Security Appliance Software=9.22.1.6
Cisco Adaptive Security Appliance Software=9.22.2
Cisco Adaptive Security Appliance Software=9.23.1
Cisco Adaptive Security Appliance Software=9.23.1.3
Cisco Secure Firewall Threat Defense=6.4.0
Cisco Secure Firewall Threat Defense=6.4.0.1
Cisco Secure Firewall Threat Defense=6.4.0.2
Cisco Secure Firewall Threat Defense=6.4.0.3
Cisco Secure Firewall Threat Defense=6.4.0.4
Cisco Secure Firewall Threat Defense=6.4.0.5
Cisco Secure Firewall Threat Defense=6.4.0.6
Cisco Secure Firewall Threat Defense=6.4.0.7
Cisco Secure Firewall Threat Defense=6.4.0.8
Cisco Secure Firewall Threat Defense=6.4.0.9
Cisco Secure Firewall Threat Defense=6.4.0.10
Cisco Secure Firewall Threat Defense=6.4.0.11
Cisco Secure Firewall Threat Defense=6.4.0.12
Cisco Secure Firewall Threat Defense=6.4.0.13
Cisco Secure Firewall Threat Defense=6.4.0.14
Cisco Secure Firewall Threat Defense=6.4.0.15
Cisco Secure Firewall Threat Defense=6.4.0.16
Cisco Secure Firewall Threat Defense=6.4.0.17
Cisco Secure Firewall Threat Defense=6.4.0.18
Cisco Secure Firewall Threat Defense=7.0.0
Cisco Secure Firewall Threat Defense=7.0.0.1
Cisco Secure Firewall Threat Defense=7.0.1
Cisco Secure Firewall Threat Defense=7.0.1.1
Cisco Secure Firewall Threat Defense=7.0.2
Cisco Secure Firewall Threat Defense=7.0.2.1
Cisco Secure Firewall Threat Defense=7.0.3
Cisco Secure Firewall Threat Defense=7.0.4
Cisco Secure Firewall Threat Defense=7.0.5
Cisco Secure Firewall Threat Defense=7.0.6
Cisco Secure Firewall Threat Defense=7.0.6.1
Cisco Secure Firewall Threat Defense=7.0.6.2
Cisco Secure Firewall Threat Defense=7.0.6.3
Cisco Secure Firewall Threat Defense=7.0.7
Cisco Secure Firewall Threat Defense=7.0.8
Cisco Secure Firewall Threat Defense=7.0.8.1
Cisco Secure Firewall Threat Defense=7.1.0
Cisco Secure Firewall Threat Defense=7.1.0.1
Cisco Secure Firewall Threat Defense=7.1.0.2
Cisco Secure Firewall Threat Defense=7.1.0.3
Cisco Secure Firewall Threat Defense=7.2.0
Cisco Secure Firewall Threat Defense=7.2.0.1
Cisco Secure Firewall Threat Defense=7.2.1
Cisco Secure Firewall Threat Defense=7.2.2
Cisco Secure Firewall Threat Defense=7.2.3
Cisco Secure Firewall Threat Defense=7.2.4
Cisco Secure Firewall Threat Defense=7.2.4.1
Cisco Secure Firewall Threat Defense=7.2.5
Cisco Secure Firewall Threat Defense=7.2.5.1
Cisco Secure Firewall Threat Defense=7.2.5.2
Cisco Secure Firewall Threat Defense=7.2.6
Cisco Secure Firewall Threat Defense=7.2.7
Cisco Secure Firewall Threat Defense=7.2.8
Cisco Secure Firewall Threat Defense=7.2.8.1
Cisco Secure Firewall Threat Defense=7.2.9
Cisco Secure Firewall Threat Defense=7.2.10
Cisco Secure Firewall Threat Defense=7.2.10.2
Cisco Secure Firewall Threat Defense=7.3.0
Cisco Secure Firewall Threat Defense=7.3.1
Cisco Secure Firewall Threat Defense=7.3.1.1
Cisco Secure Firewall Threat Defense=7.3.1.2
Cisco Secure Firewall Threat Defense=7.4.0
Cisco Secure Firewall Threat Defense=7.4.1
Cisco Secure Firewall Threat Defense=7.4.1.1
Cisco Secure Firewall Threat Defense=7.4.2
Cisco Secure Firewall Threat Defense=7.4.2.1
Cisco Secure Firewall Threat Defense=7.4.2.2
Cisco Secure Firewall Threat Defense=7.4.2.3
Cisco Secure Firewall Threat Defense=7.4.2.4
Cisco Secure Firewall Threat Defense=7.6.0
Cisco Secure Firewall Threat Defense=7.6.1
Cisco Secure Firewall Threat Defense=7.6.2
Cisco Secure Firewall Threat Defense=7.6.2.1
Cisco Secure Firewall Threat Defense=7.7.0
Cisco Secure Firewall Threat Defense=7.7.10
Cisco Secure Firewall Threat Defense=7.7.10.1

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-2026-20100?

The severity of CVE-2026-20100 is rated as medium due to its potential impact on device availability.

2

How do I fix CVE-2026-20100?

To mitigate CVE-2026-20100, update to the latest version of Cisco Secure Firewall ASA or FTD Software as recommended by Cisco.

3

What type of attack does CVE-2026-20100 allow?

CVE-2026-20100 allows an authenticated remote attacker with a valid VPN connection to cause the affected device to reload unexpectedly.

4

Which Cisco products are affected by CVE-2026-20100?

CVE-2026-20100 affects Cisco Secure Firewall Adaptive Security Appliance (ASA) Software and Secure Firewall Threat Defense (FTD) Software.

5

Is CVE-2026-20100 remotely exploitable?

Yes, CVE-2026-20100 can be exploited remotely by an authenticated user who has a valid VPN connection.

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