CVE-2026-20073
CWE-284Published: March 4, 2026· Updated: Mar 5, 2026
Official Description
A vulnerability in Cisco Secure Firewall Adaptive Security Appliance (ASA) Software and Cisco Secure Firewall Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to send traffic that should be denied through an affected device.
This vulnerability is due to improper error handling when an affected device that is joining a cluster runs out of memory while replicating access control rules. An attacker could exploit this vulnerability by sending traffic that should be blocked through the device. A successful exploit could allow the attacker to bypass access controls and reach devices in protected networks.
Technical Analysis
CVE-2026-20073 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.
The vulnerability requires no privileges and no user interaction, making it a prime target for automated exploitation campaigns and worm-like propagation.
The vulnerability has a "Changed" scope, meaning successful exploitation can impact components beyond the vulnerable component itself — such as the host operating system or adjacent services.
CVSS v3.1 Vector Breakdown
Affected Vendors & Products
Exploit & PoC Resources
All References (1)
Quick Facts
Related CVEs (CWE-284)
Recommended Actions
- →Apply vendor patches immediately
- →Monitor CVE-2026-20073 in threat intel feeds
- →Review IDS/IPS signatures for exploitation attempts