CVE-2026-1064 identifies a command injection vulnerability in bastillion-io Bastillion versions 4.0.0 and 4.0.1, located in the System Management Module's source file SystemKtrl.java. This vulnerability arises from improper handling of input that is passed to system commands, allowing an attacker to inject and execute arbitrary commands on the underlying operating system. The attack vector is remote network access, and the attacker requires high privileges on the Bastillion system but does not need user interaction to exploit the flaw. The vulnerability affects the confidentiality, integrity, and availability of the affected system by enabling unauthorized command execution, potentially leading to full system compromise. Although the vendor has not responded and no patches are currently available, the exploit code has been publicly disclosed, increasing the risk of exploitation. Bastillion is typically used as a centralized SSH session management and privileged access management tool, making it a high-value target for attackers seeking lateral movement or privilege escalation within enterprise environments. The CVSS 4.0 score of 5.1 reflects medium severity, considering the ease of remote exploitation without user interaction but requiring high privileges. No known active exploitation in the wild has been reported yet, but the public availability of the exploit increases urgency for mitigation.

For European organizations, this vulnerability poses a significant risk to systems that rely on Bastillion for managing privileged SSH access. Successful exploitation could allow attackers to execute arbitrary commands with high privileges, potentially leading to unauthorized data access, system manipulation, or disruption of critical services. This could impact confidentiality by exposing sensitive credentials or data, integrity by altering system configurations or logs, and availability by disrupting Bastillion services or the underlying host. Organizations in sectors such as finance, government, energy, and telecommunications, which often use Bastillion for secure access management, could face operational disruptions or data breaches. The public disclosure of the exploit increases the likelihood of opportunistic attacks, especially in environments where Bastillion instances are exposed to untrusted networks or lack proper access controls. The absence of vendor patches further exacerbates the risk, requiring organizations to implement compensating controls promptly.

1. Restrict network access to Bastillion instances by implementing strict firewall rules and VPN-only access to limit exposure to trusted users and networks. 2. Monitor and audit Bastillion logs for unusual command execution patterns or unauthorized access attempts. 3. Apply strict input validation and sanitization controls where possible, especially if custom integrations or scripts interact with Bastillion's System Management Module. 4. Isolate Bastillion servers in segmented network zones with limited connectivity to critical infrastructure. 5. Regularly update Bastillion software and subscribe to vendor advisories to apply patches promptly once available. 6. Employ host-based intrusion detection systems (HIDS) to detect anomalous command executions on Bastillion hosts. 7. Consider temporary disabling or limiting the use of the vulnerable System Management Module if feasible until a patch is released. 8. Educate administrators on the risks and ensure privileged accounts are protected with strong authentication and monitored for suspicious activity.