CVE-2026-20023: Medium severity Cisco Secure Firewall Adaptive Security Appliance (ASA) Software vulnerability

Published Mar 4, 2026
·
Updated

A vulnerability in the OSPF protocol of Cisco Secure Firewall Adaptive Security Appliance (ASA) Software and Cisco Secure Firewall Threat Defense (FTD) Software could allow an unauthenticated, adjacent attacker to corrupt memory on an affected device, resulting in a denial of service (DoS) condition. This vulnerability is due to memory corruption when parsing OSPF protocol packets. An attacker could exploit this vulnerability by sending crafted OSPF packets to an affected device. A successful exploit could allow the attacker to cause memory corruption causing the affected device to reboot, resulting in a DoS condition.

Affected Software

236 affected components
Cisco Secure Firewall Adaptive Security Appliance (ASA) Software
Cisco Secure Firewall Threat Defense (FTD) Software
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=7.4.3
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=7.7.10.1
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=9.16.4.85
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=9.18.4.66
Cisco Adaptive Security Appliance Software=9.18.4.67
Cisco Adaptive Security Appliance Software=9.18.4.68
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=9.20.4
Cisco Adaptive Security Appliance Software=9.20.4.7
Cisco Adaptive Security Appliance Software=9.20.4.10
Cisco Adaptive Security Appliance Software=9.20.4.14
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=9.22.2.9
Cisco Adaptive Security Appliance Software=9.22.2.13
Cisco Adaptive Security Appliance Software=9.22.2.14
Cisco Adaptive Security Appliance Software=9.23.1
Cisco Adaptive Security Appliance Software=9.23.1.7
Cisco Adaptive Security Appliance Software=9.23.1.13
Cisco Adaptive Security Appliance Software=9.23.1.19
Cisco Adaptive Security Appliance Software=9.23.1.22

Event History

Mar 4, 2026
CVE Published
via MITRE·06:35 PM
Data Sourced
via MITRE·06:35 PM
DescriptionSeverityWeakness
Data Sourced
via NVD·07:16 PM
DescriptionSeverityWeaknessAffected Software
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Frequently Asked Questions

1

What is the severity of CVE-2026-20023?

The severity of CVE-2026-20023 is classified as high, indicating a significant risk to affected systems.

2

How do I fix CVE-2026-20023?

To fix CVE-2026-20023, it is recommended to update to the latest version of the affected Cisco secure firewall software.

3

Who is affected by CVE-2026-20023?

CVE-2026-20023 affects users of Cisco Secure Firewall Adaptive Security Appliance (ASA) Software and Cisco Secure Firewall Threat Defense (FTD) Software.

4

What type of attack can exploit CVE-2026-20023?

CVE-2026-20023 can be exploited by an unauthenticated, adjacent attacker aiming to corrupt device memory, leading to a denial of service (DoS).

5

What devices are impacted by CVE-2026-20023?

Devices impacted by CVE-2026-20023 include those running Cisco Secure Firewall Adaptive Security Appliance and Cisco Secure Firewall Threat Defense software.

Company

Resources

Contact

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