CVE-2026-20023 — MEDIUM (6.1)

Vulnerability Description

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.

CVSS Score

6.1

MEDIUM

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

Attack Vector

ADJACENT_NETWORK

Attack Complexity

HIGH

Privileges Required

NONE

User Interaction

NONE

Scope

CHANGED

Confidentiality

NONE

Integrity

NONE

Availability

HIGH

Affected Products

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

Related Weaknesses (CWE)

CWE-787

References

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

FAQ

What is CVE-2026-20023?

CVE-2026-20023 is a vulnerability with a CVSS score of 6.1 (MEDIUM). 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, adjacen...

How severe is CVE-2026-20023?

CVE-2026-20023 has been rated MEDIUM with a CVSS base score of 6.1/10. Review the CVSS metrics above for detailed severity breakdown.

Is there a patch for CVE-2026-20023?

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