CVE-2026-20020 — MEDIUM (6.8)

Vulnerability 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.

CVSS Score

6.8

MEDIUM

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

Attack Vector

ADJACENT_NETWORK

Attack Complexity

LOW

Privileges Required

LOW

User Interaction

NONE

Scope

CHANGED

Confidentiality

NONE

Integrity

NONE

Availability

HIGH

Affected Products

Vendor	Product	Versions
Cisco	Adaptive Security Appliance Software	9.12.1
Cisco	Firepower Threat Defense	6.4.0

Related Weaknesses (CWE)

CWE-20

References

https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/ciVendor Advisory

FAQ

What is CVE-2026-20020?

CVE-2026-20020 is a vulnerability with a CVSS score of 6.8 (MEDIUM). 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 unexpec...

How severe is CVE-2026-20020?

CVE-2026-20020 has been rated MEDIUM with a CVSS base score of 6.8/10. Review the CVSS metrics above for detailed severity breakdown.

Is there a patch for CVE-2026-20020?

Check the references section above for vendor advisories and patch information. Affected products include: Cisco Adaptive Security Appliance Software, Cisco Firepower Threat Defense.