CVE-2025-66005 is a vulnerability classified under CWE-863 (Improper Authorization) affecting InputPlumber, an open-source tool hosted on GitHub by ShadowBlip. The issue arises from the lack of proper authorization checks on the InputManager D-Bus interface in InputPlumber versions before 0.63.0. D-Bus is a widely used inter-process communication system in Linux environments, enabling different software components to communicate. Improper authorization on this interface means that any local user with access to the session bus can invoke privileged operations without sufficient permission checks. This can lead to multiple attack vectors: local denial-of-service by disrupting input management, information disclosure by accessing sensitive session data, or privilege escalation by executing commands with higher privileges within the active user session. The vulnerability does not require prior authentication but does require local access and some user interaction, such as running a crafted command or script. The CVSS 4.0 score of 8.5 reflects a high severity due to the high impact on confidentiality, integrity, and availability, combined with relatively low attack complexity and no privileges required. No public exploits have been reported yet, but the potential for damage is significant, especially in multi-user or shared environments. The vulnerability was reserved in November 2025 and published in January 2026, indicating recent discovery and disclosure. The absence of patch links suggests that users must monitor the official repository for updates or apply mitigations manually. This vulnerability highlights the critical need for robust authorization mechanisms on IPC interfaces like D-Bus to prevent local privilege escalation and session compromise.

For European organizations, the impact of CVE-2025-66005 can be substantial, particularly in sectors relying heavily on Linux-based systems and multi-user environments such as research institutions, telecommunications, and critical infrastructure. Exploitation could allow malicious insiders or compromised local users to disrupt services (denial-of-service), access confidential session data, or escalate privileges to perform unauthorized actions, potentially leading to broader system compromise. This is especially concerning in environments where InputPlumber manages input devices or session controls, as attackers could manipulate user input or capture sensitive information. The vulnerability undermines the security assumptions of session isolation and user privilege boundaries, increasing the risk of lateral movement and data breaches. Given the high CVSS score and the nature of the flaw, organizations face risks to confidentiality, integrity, and availability of their systems. The lack of known exploits in the wild provides a window for proactive defense, but the vulnerability’s presence in open-source software used across various distributions means the attack surface is broad. European entities with stringent data protection regulations (e.g., GDPR) must consider the potential compliance and reputational risks arising from exploitation.

1. Upgrade InputPlumber to version 0.63.0 or later as soon as it becomes available to ensure the authorization flaw is patched. 2. Until patches are applied, restrict local access to the D-Bus session bus and the InputManager interface by enforcing strict Linux user permissions and access control lists (ACLs). 3. Implement mandatory access control (MAC) frameworks such as SELinux or AppArmor to confine InputPlumber and limit its interaction scope. 4. Monitor local user activities and audit D-Bus calls related to InputManager for unusual or unauthorized access patterns. 5. Educate system administrators and users about the risks of running untrusted local code or scripts that could exploit this vulnerability. 6. Consider isolating critical user sessions or input management services in containers or sandboxes to reduce the impact of potential exploitation. 7. Regularly review and harden IPC mechanisms and authorization policies in multi-user Linux environments to prevent similar flaws. 8. Coordinate with Linux distribution maintainers and security teams to track patch releases and advisories related to InputPlumber.