CVE-2026-22601 is a command injection vulnerability identified in OpenProject, an open-source web-based project management software widely used for collaborative project tracking and management. The flaw exists in versions 16.6.1 and earlier, where a registered administrator can exploit improper neutralization of special characters in the configuration of the sendmail binary path. By manipulating this configuration and triggering a test email, the attacker can execute arbitrary system commands with the privileges of the OpenProject application. This vulnerability is classified under CWE-77, indicating improper sanitization of inputs used in command execution contexts. The CVSS 4.0 base score is 8.6, reflecting a high severity due to network exploitability (AV:N), low attack complexity (AC:L), no user interaction (UI:N), and the requirement of high privileges (PR:H). The vulnerability impacts confidentiality, integrity, and availability as arbitrary commands can lead to data exfiltration, system manipulation, or denial of service. The issue was publicly disclosed on January 10, 2026, and patched in version 16.6.2. No public exploit code or active exploitation has been reported yet, but the presence of administrative access as a prerequisite means insider threats or compromised admin accounts could be leveraged. The vulnerability does not require user interaction, making automated exploitation feasible once admin access is obtained. The lack of sandboxing or command restrictions in the sendmail path configuration is the root cause. This vulnerability underscores the importance of input validation and secure configuration management in web applications handling system-level commands.

For European organizations, the impact of CVE-2026-22601 can be significant. OpenProject is commonly used in various sectors including government, manufacturing, IT, and engineering firms across Europe for managing complex projects. Exploitation could lead to unauthorized command execution on servers hosting OpenProject, potentially compromising sensitive project data, intellectual property, and internal communications. Attackers could pivot from the compromised server to other internal systems, leading to broader network breaches. The integrity of project timelines and deliverables could be undermined, causing operational disruptions. Confidential information related to EU-funded projects or critical infrastructure could be exposed, violating data protection regulations such as GDPR. Additionally, availability impacts could disrupt project management workflows, delaying critical initiatives. The requirement for administrator privileges limits the attack surface but also highlights the risk of insider threats or credential compromise. Organizations with weak access controls or insufficient monitoring are particularly vulnerable. The absence of known exploits in the wild currently reduces immediate risk but does not eliminate the threat, especially as exploit code may emerge post-disclosure.

1. Immediate upgrade of OpenProject installations to version 16.6.2 or later to apply the official patch addressing the vulnerability. 2. Restrict administrator privileges strictly to trusted personnel and enforce strong authentication mechanisms, including multi-factor authentication (MFA), to reduce the risk of credential compromise. 3. Audit and monitor configurations related to sendmail or other system command integrations within OpenProject to detect unauthorized changes. 4. Implement network segmentation to isolate project management servers from critical internal networks, limiting lateral movement in case of compromise. 5. Employ application-level input validation and sanitization controls where possible to prevent injection attacks. 6. Conduct regular security training for administrators to recognize and prevent misuse of privileged access. 7. Monitor logs for unusual command execution patterns or email sending activities that could indicate exploitation attempts. 8. Consider deploying runtime application self-protection (RASP) or web application firewalls (WAF) with custom rules to detect and block suspicious command injection attempts targeting OpenProject. 9. Establish incident response procedures specifically addressing potential exploitation of administrative interfaces. 10. Review and limit the use of sendmail or similar binaries to only necessary functions and consider alternative secure mail configurations.