CVE-2026-20023: exploitation status and patch state

CVE-2026-20023 · CVSS 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, 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.

Is CVE-2026-20023 exploited?

• Not in the CISA KEV catalog.
• Public exploit code: none found in monitored sources.

Which products and versions are affected?

No affected package list recorded here yet.

Is there a patch?

No patch identifier recorded here yet.

What PlainSec published about CVE-2026-20023

• OSPF Denial-of-Service Vulnerabilities in Cisco Secure Firewalls (2026-03-27)

Primary sources

• NVD record

What this record does not say

• No EPSS score.
• No affected package data.
• No patch identifier.

KEV and EPSS are re-checked daily. Record last updated 2026-08-11.