Executive brief
Cisco's Secure Firewall appliances (ASA, FTD, and FMC software) contain multiple security vulnerabilities introduced through incorrect comparison logic in security-sensitive code paths. An authenticated attacker with network access can exploit these flaws to bypass access controls, crash systems, or gain unauthorized privileges, potentially allowing full compromise of network security infrastructure that protects critical business operations.
Technical details
CVE-2026-20333 specifically addresses incorrect comparison conditions (CWE-697) discovered during Cisco's internal security review and grouped with seven related vulnerabilities across multiple CWE categories (access control, exception handling, data validation, and resource management). The vulnerability requires authentication and network access; the appliances are network-reachable components. An attacker can exploit these flaws to bypass security controls, cause denial of service, or achieve privilege escalation depending on the underlying weakness. Cisco has released software patches and explicitly states there are no workarounds; immediate upgrade is required.
Affected products
- Cisco Secure Firewall Adaptive Security Appliance Software <UNKNOWN>
- Cisco Secure Firewall Threat Defense Software <UNKNOWN>
- Cisco Secure Firewall Management Center Software <UNKNOWN>
Timeline
- 2026-09-16: disclosed: CVE-2026-20333 published
- 2026-09-16: patched: Software updates released