CVE-2025-26155 is an Untrusted Search Path vulnerability (CWE-426) identified in NCP Secure Enterprise Client 13.18 and NCP Secure Entry Windows Client 13.19. The vulnerability occurs because the affected software does not securely specify the full path when loading executable files or libraries, instead relying on the system's search path which may include untrusted directories. This can allow an attacker with the ability to place a malicious executable in a directory that is searched before the legitimate one to execute arbitrary code with the same privileges as the client software. The CVSS v3.1 base score is 9.8, reflecting network attack vector (AV:N), low attack complexity (AC:L), no privileges required (PR:N), no user interaction (UI:N), and high impact on confidentiality, integrity, and availability (C:H/I:H/A:H). The vulnerability is critical because it can be exploited remotely without authentication or user interaction, potentially leading to full system compromise. Although no public exploits are currently known, the nature of the vulnerability and the high CVSS score suggest that exploitation could be straightforward once a malicious actor gains access to a suitable location in the file system. The affected products are widely used in enterprise environments to provide secure VPN access, making this vulnerability a significant risk for organizations relying on these clients for secure communications.

For European organizations, the impact of CVE-2025-26155 is substantial. Successful exploitation can lead to complete compromise of endpoint devices running the vulnerable NCP clients, resulting in unauthorized access to sensitive corporate networks and data. This threatens confidentiality by exposing sensitive communications, integrity by allowing alteration of data or configurations, and availability by potentially disrupting VPN connectivity or causing system instability. Critical sectors such as finance, government, healthcare, and energy that depend on secure VPN connections for remote work and inter-office communications are particularly at risk. The vulnerability's ease of exploitation without authentication or user interaction increases the likelihood of targeted attacks or widespread automated exploitation campaigns. Additionally, compromised endpoints could serve as footholds for lateral movement within networks, escalating the overall risk to European enterprises. The absence of known exploits currently provides a window for proactive mitigation, but the critical severity demands urgent attention.

1. Monitor NCP’s official channels for security patches addressing CVE-2025-26155 and apply updates immediately upon release. 2. Until patches are available, restrict write permissions on directories included in the client’s search path to prevent attackers from placing malicious executables. 3. Implement application whitelisting to ensure only trusted executables can run on endpoints using the NCP clients. 4. Conduct regular audits of the file system paths used by the VPN clients to detect unauthorized files or changes. 5. Employ endpoint detection and response (EDR) solutions to monitor for suspicious process creation or execution related to the NCP clients. 6. Educate IT staff and users about the risks of untrusted search paths and the importance of maintaining secure configurations. 7. Consider network segmentation and strict access controls to limit the impact of a compromised endpoint. 8. Review and harden VPN client deployment configurations to minimize exposure to this vulnerability.