Access Control Bypass in Cisco Secure Firewall Software

CVE-2026-20121

What is CVE-2026-20121?

A vulnerability in the access control list (ACL) implementation of Cisco Secure Firewall Adaptive Security Appliance (ASA) and Threat Defense (FTD) software could be exploited by an unauthenticated remote attacker. This issue arises from a logic defect in the group access control policies, allowing attackers to circumvent established access controls. By sending specific traffic that should otherwise be blocked, an attacker could gain access to devices within secure networks, posing significant threats to confidentiality and integrity.

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