CVE-2025-26155 identifies an Untrusted Search Path vulnerability in NCP Secure Enterprise Client version 13.18 and NCP Secure Entry Windows Client version 13.19. An Untrusted Search Path vulnerability occurs when an application loads executables or libraries from directories that are not securely specified, allowing attackers to place malicious files in those directories. When the application subsequently loads these files, it may execute attacker-controlled code. In this case, the affected NCP VPN clients on Windows do not properly validate or restrict the directories from which they load components, potentially enabling privilege escalation or arbitrary code execution. This vulnerability does not require user interaction but does require the attacker to have some level of local or network access to influence the search path, such as by placing malicious DLLs or executables in a directory that the client searches before the legitimate one. No CVSS score is assigned yet, and no public exploits are known, but the risk is significant given the nature of VPN clients as security-critical software. The vulnerability was reserved in early 2025 and published in late 2025, indicating a recent discovery. The lack of patch links suggests that fixes may not yet be available, emphasizing the need for interim mitigations. The vulnerability affects confidentiality and integrity by potentially allowing attackers to bypass VPN security controls or execute code with elevated privileges. Organizations relying on these NCP clients should be aware of this risk and prepare to apply vendor patches once released.

For European organizations, this vulnerability poses a risk of unauthorized code execution within VPN client environments, potentially compromising secure remote access infrastructure. Exploitation could lead to privilege escalation, allowing attackers to intercept or manipulate VPN traffic, steal credentials, or deploy further malware inside corporate networks. This undermines confidentiality and integrity of communications and data accessed via the VPN. Given the widespread use of NCP VPN solutions in sectors such as government, finance, and critical infrastructure in Europe, successful exploitation could disrupt secure operations and lead to data breaches. The absence of known exploits reduces immediate risk but does not eliminate the threat, especially as attackers often target VPN clients to gain initial footholds. The vulnerability's impact is amplified in environments where endpoint security is weak or where users have elevated privileges. Organizations with remote workforces relying on these clients are particularly vulnerable. Without patches, the risk remains until mitigations are applied, potentially exposing sensitive European data and systems to compromise.

To mitigate this vulnerability, organizations should first restrict write permissions on directories included in the VPN client's search path to prevent unauthorized file placement. Administrators should verify that the VPN clients are running with least privilege and that users do not have unnecessary local administrative rights. Monitoring for unexpected DLL or executable files in directories used by the VPN client can help detect exploitation attempts. Network segmentation and endpoint detection and response (EDR) tools should be employed to identify suspicious activity related to the VPN client processes. Organizations should engage with NCP to obtain patches or updates as soon as they become available and prioritize their deployment. Until patches are released, consider using application whitelisting to prevent execution of unauthorized binaries. Educate users about the risks of running untrusted software and ensure that VPN client software is installed only from trusted sources. Regularly audit system configurations to ensure compliance with security best practices regarding path and file permissions.