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CVE-2026-20020

MEDIUMCVSS 5.7/10EPSS 0.25%

Last modified

CVE-2026-20020 is a medium-severity vulnerability rated 5.7/10 on the CVSS scale. 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. EPSS estimates a 0.25% chance of exploitation in the next 30 days.

Description

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.

Metrics

CVSS 3.1
5.7/10

CVSS:3.1/AV:A/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

EPSS Probability
0.25%

16.3th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

VendorProductVersions
CiscoAdaptive Security Appliance Software9.12.1
CiscoAdaptive Security Appliance Software9.12.1.2
CiscoAdaptive Security Appliance Software9.12.1.3
CiscoAdaptive Security Appliance Software9.12.2
CiscoAdaptive Security Appliance Software9.12.2.1
CiscoAdaptive Security Appliance Software9.12.2.4
CiscoAdaptive Security Appliance Software9.12.2.5
CiscoAdaptive Security Appliance Software9.12.2.9
CiscoAdaptive Security Appliance Software9.12.3
CiscoAdaptive Security Appliance Software9.12.3.2
CiscoAdaptive Security Appliance Software9.12.3.7
CiscoAdaptive Security Appliance Software9.12.3.9
CiscoAdaptive Security Appliance Software9.12.3.12
CiscoAdaptive Security Appliance Software9.12.4
CiscoAdaptive Security Appliance Software9.12.4.2
CiscoAdaptive Security Appliance Software9.12.4.4
CiscoAdaptive Security Appliance Software9.12.4.7
CiscoAdaptive Security Appliance Software9.12.4.8
CiscoAdaptive Security Appliance Software9.12.4.10
CiscoAdaptive Security Appliance Software9.12.4.13
CiscoAdaptive Security Appliance Software9.12.4.18
CiscoAdaptive Security Appliance Software9.12.4.24
CiscoAdaptive Security Appliance Software9.12.4.26
CiscoAdaptive Security Appliance Software9.12.4.29
CiscoAdaptive Security Appliance Software9.12.4.30
CiscoAdaptive Security Appliance Software9.12.4.35
CiscoAdaptive Security Appliance Software9.12.4.37
CiscoAdaptive Security Appliance Software9.12.4.38
CiscoAdaptive Security Appliance Software9.12.4.39
CiscoAdaptive Security Appliance Software9.12.4.40
CiscoAdaptive Security Appliance Software9.12.4.41
CiscoAdaptive Security Appliance Software9.12.4.47
CiscoAdaptive Security Appliance Software9.12.4.48
CiscoAdaptive Security Appliance Software9.12.4.50
CiscoAdaptive Security Appliance Software9.12.4.52
CiscoAdaptive Security Appliance Software9.12.4.54
CiscoAdaptive Security Appliance Software9.12.4.55
CiscoAdaptive Security Appliance Software9.12.4.56
CiscoAdaptive Security Appliance Software9.12.4.58
CiscoAdaptive Security Appliance Software9.12.4.62
CiscoAdaptive Security Appliance Software9.12.4.65
CiscoAdaptive Security Appliance Software9.12.4.67
CiscoAdaptive Security Appliance Software9.16.1
CiscoAdaptive Security Appliance Software9.16.1.28
CiscoAdaptive Security Appliance Software9.16.2
CiscoAdaptive Security Appliance Software9.16.2.3
CiscoAdaptive Security Appliance Software9.16.2.7
CiscoAdaptive Security Appliance Software9.16.2.11
CiscoAdaptive Security Appliance Software9.16.2.13
CiscoAdaptive Security Appliance Software9.16.2.14

Showing 50 of 221 affected configurations. See NVD for the full list.

References

Timeline

Published
Last Modified
Status
Analyzed

Frequently Asked Questions

What is CVE-2026-20020?
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.
How severe is CVE-2026-20020?
CVE-2026-20020 has a CVSS score of 5.7/10 (MEDIUM severity). The EPSS model estimates a 0.25% probability of exploitation in the next 30 days.
How do I fix CVE-2026-20020?
Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2026-20020?

Run a free Strix scan to check your systems for this vulnerability.

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Source: NVD / NIST