CVE-2025-12026 is an out-of-bounds write vulnerability classified under CWE-787 found in the certificate request command of WatchGuard Fireware OS. This vulnerability affects multiple versions of Fireware OS, specifically versions 12.0 up to 12.11.4, 12.5 up to 12.5.13, and 2025.1 up to 2025.1.2. The flaw arises when an authenticated user with privileged access issues specially crafted CLI commands related to certificate requests, causing the system to write data outside the intended memory bounds. This memory corruption can lead to arbitrary code execution with high privileges, potentially allowing attackers to take full control of the affected device. The vulnerability does not require user interaction and can be exploited remotely over the network, as indicated by the CVSS vector (AV:N). The attack complexity is low, and no additional authentication beyond privileged access is needed. The vulnerability impacts confidentiality, integrity, and availability, as arbitrary code execution could lead to data breaches, device manipulation, or denial of service. Currently, there are no known exploits in the wild, but the high CVSS score (8.6) reflects the serious risk posed by this vulnerability. The lack of available patches at the time of reporting necessitates immediate risk mitigation by limiting access and monitoring. WatchGuard Fireware OS is widely used in network security appliances, including firewalls and unified threat management devices, making this vulnerability critical for organizations relying on these products for perimeter defense and secure communications.

For European organizations, the impact of CVE-2025-12026 could be significant due to the widespread use of WatchGuard Fireware OS in enterprise and government network security infrastructures. Successful exploitation could allow attackers to gain full control over network security devices, leading to unauthorized access to sensitive data, disruption of network services, and potential lateral movement within corporate networks. This could compromise confidentiality of communications, integrity of network traffic filtering, and availability of critical security functions. Organizations in sectors such as finance, healthcare, government, and critical infrastructure are particularly at risk, as compromise of security appliances could facilitate large-scale data breaches or sabotage. Additionally, the vulnerability’s exploitation could undermine trust in network defenses, complicate incident response, and increase regulatory and compliance risks under European data protection laws like GDPR. The absence of known exploits currently provides a window for proactive mitigation, but the ease of exploitation and high privileges required mean insider threats or compromised administrators pose a serious risk vector.

1. Immediately restrict CLI access to WatchGuard Fireware OS devices to only the most trusted and necessary privileged users, employing strict role-based access controls. 2. Monitor and audit all privileged CLI command usage, especially certificate request commands, to detect anomalous or unauthorized activity. 3. Implement network segmentation and firewall rules to limit management interface exposure to trusted networks and IP addresses only. 4. Deploy multi-factor authentication (MFA) for all privileged accounts accessing Fireware OS devices to reduce risk of credential compromise. 5. Regularly back up device configurations and logs to enable rapid recovery and forensic analysis if exploitation occurs. 6. Stay alert for official patches or updates from WatchGuard and apply them promptly once released. 7. Conduct internal vulnerability assessments and penetration tests focusing on Fireware OS devices to identify potential exploitation paths. 8. Educate administrators on the risks of executing unverified CLI commands and enforce strict change management procedures. 9. Consider deploying intrusion detection or prevention systems capable of recognizing suspicious CLI command patterns targeting Fireware OS. 10. Collaborate with WatchGuard support and security communities to share threat intelligence and mitigation best practices.