CVE-2026-20020: Input Validation

Published Mar 4, 2026
·
Updated

A vulnerability in the OSPF protocol of Cisco Secure Firewall ASA Software and Cisco Secure FTD Software could allow an unauthenticated, adjacent attacker to cause an affected device to reload unexpectedly, resulting in a DoS condition. If OSPF authentication is enabled, the attacker must know the secret key to exploit this vulnerability. This vulnerability is due to insufficient input validation when processing OSPF update packets. An attacker could exploit this vulnerability by sending crafted OSPF update packets. A successful exploit could allow the attacker to create a buffer overflow, causing the affected device to reload, resulting in a DoS condition.

Affected Software

223 affected components
Cisco Secure Firewall ASA Software
Cisco Secure 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=9.16.4.85
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=9.19.1
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 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

Event History

Mar 4, 2026
CVE Published
via MITRE·06:34 PM
Data Sourced
via MITRE·06:34 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-2026-20020?

CVE-2026-20020 is classified as a critical severity vulnerability.

2

How do I fix CVE-2026-20020?

To fix CVE-2026-20020, you should apply the latest patches provided by Cisco for the affected software.

3

What impact does CVE-2026-20020 have on my network?

CVE-2026-20020 can lead to unexpected device reloads, creating a denial of service (DoS) condition.

4

Who is affected by CVE-2026-20020?

CVE-2026-20020 affects users of Cisco Secure Firewall ASA Software and Cisco Secure FTD Software.

5

Can CVE-2026-20020 be exploited remotely?

CVE-2026-20020 requires an adjacent attacker, meaning exploitation cannot be conducted remotely.

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