CVE-2026-20003 is an SQL injection vulnerability identified in the REST API component of Cisco Secure Firewall Management Center (FMC) software. The root cause is improper neutralization of special elements in user-supplied input, which allows an authenticated attacker to inject malicious SQL commands. The vulnerability affects a broad range of FMC versions from 7.0.0 up to 7.7.10.1. Exploitation requires valid user credentials with elevated roles such as Administrator, Security Approver, Intrusion Admin, Access Admin, or Network Admin. By sending crafted REST API requests, an attacker can manipulate SQL queries executed by the FMC backend database, resulting in unauthorized read access to sensitive database contents and certain files on the underlying operating system. This could facilitate information disclosure, aiding further attacks or reconnaissance. The vulnerability does not impact integrity or availability directly but compromises confidentiality. The CVSS v3.1 base score is 4.9 (medium), reflecting network attack vector, low attack complexity, high privileges required, no user interaction, and high confidentiality impact. No public exploits or active exploitation have been reported to date. The vulnerability underscores the importance of strict input validation and secure coding practices in REST API implementations, especially for security management platforms that control critical network infrastructure.

The primary impact of CVE-2026-20003 is unauthorized disclosure of sensitive information stored within the Cisco FMC database and potentially sensitive files on the underlying operating system. This can expose network configuration details, security policies, logs, and other critical data that attackers could leverage for lateral movement, privilege escalation, or further targeted attacks. Since FMC is widely deployed in enterprise and service provider environments to manage firewall policies and network security, compromise could undermine the overall security posture of affected organizations. The requirement for high-privilege credentials limits exploitation to insiders or attackers who have already breached initial defenses, but the vulnerability still poses a significant risk if such credentials are compromised or misused. The lack of impact on integrity or availability reduces the risk of direct service disruption but increases the risk of stealthy data exfiltration. Organizations relying on Cisco FMC for perimeter and internal network security management could face regulatory compliance issues and reputational damage if sensitive data is leaked. The broad range of affected versions and the critical role of FMC in network defense amplify the potential impact globally.

1. Apply official patches or updates from Cisco as soon as they become available for the affected FMC versions to remediate the vulnerability. 2. Restrict access to the FMC REST API to trusted administrators only and enforce strong authentication mechanisms, including multi-factor authentication (MFA) for all privileged accounts. 3. Conduct regular audits of user accounts and roles to ensure that only necessary personnel have high-privilege roles such as Administrator or Network Admin. 4. Implement network segmentation and firewall rules to limit access to the FMC management interface from untrusted networks. 5. Monitor FMC logs and network traffic for unusual API requests or patterns indicative of attempted SQL injection or unauthorized access. 6. Employ Web Application Firewalls (WAFs) or API gateways with SQL injection detection and prevention capabilities in front of the FMC REST API endpoints. 7. Educate administrators on secure credential management and the risks of credential compromise. 8. Consider deploying intrusion detection/prevention systems (IDS/IPS) tuned to detect exploitation attempts targeting Cisco FMC. 9. Regularly back up FMC configurations and data to enable recovery in case of compromise. 10. Engage in vulnerability scanning and penetration testing focused on the FMC environment to proactively identify and remediate weaknesses.