What is the CVSS score of CVE-2026-20023?

CVE-2026-20023 has a CVSS 3.1 base score of 6.1 (Medium). CVSS vector: CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:C/C:N/I:N/A:H. EPSS exploitation probability: 0.0%.

Which versions of Cisco are affected by CVE-2026-20023?

CVE-2026-20023 presents moderate security risk, a out-of-bounds write vulnerability rated CVSS 6.1. Exploitation could cause memory corruption or application crashes.

How to fix or mitigate CVE-2026-20023?

Within 30 days: Identify affected systems and apply vendor patches as part of regular patch cycle. Monitor vendor channels for patch availability.

Cisco CVE-2026-20023

MEDIUM

Out-of-bounds Write (CWE-787)

2026-03-04 psirt@cisco.com

Cisco Memory Corruption Denial Of Service Buffer Overflow

6.1

CVSS 3.1 · NVD

Severity by source

NVD PRIMARY

6.1 MEDIUM

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

Primary rating from NVD · only source for this CVE.

CVSS VectorNVD

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

Attack Vector

Adjacent

Attack Complexity

High

Privileges Required

None

User Interaction

None

Scope

Changed

Confidentiality

None

Integrity

None

Availability

High

Lifecycle Timeline

Analysis Generated

Mar 12, 2026 - 22:05 vuln.today

CVE Published

Mar 04, 2026 - 19:16 nvd

MEDIUM 6.1

DescriptionCVE.org

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.

AnalysisAI

Memory corruption in Cisco Secure Firewall ASA and FTD OSPF packet processing allows adjacent, unauthenticated attackers to crash affected devices by sending crafted protocol packets. The vulnerability results in device reboot and denial of service, with no authentication or user interaction required. No patch is currently available.

Technical ContextAI

Classified as CWE-787 (Out-of-bounds Write). 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