CVE-2025-26169 is a high-severity local privilege escalation vulnerability affecting the IXON VPN Client versions prior to 1.4.4 on Windows platforms. The root cause is an incorrect permission assignment (CWE-732) related to a temporary configuration file used by the VPN client. Specifically, the application creates a temporary configuration file in a directory that is world-writable, allowing any local user with low privileges to overwrite this file due to a race condition. Because the VPN client executes code from this configuration file, an attacker can inject malicious code or commands that the client will run with SYSTEM-level privileges. This effectively allows an unprivileged local user to escalate their privileges to SYSTEM, the highest level on Windows, gaining full control over the affected machine. The vulnerability does not require prior authentication or user interaction, but exploitation requires local access to the system. The CVSS v3.1 base score is 8.1, reflecting high impact on confidentiality, integrity, and availability, with attack vector local, high attack complexity, no privileges required, no user interaction, and scope changed due to SYSTEM-level escalation. No known exploits are currently reported in the wild, and no patches have been linked yet, indicating that organizations using IXON VPN Client should prioritize mitigation and monitoring to prevent exploitation once the patch is available.

For European organizations, this vulnerability poses a significant risk, especially for those relying on IXON VPN Client for secure remote access and industrial control systems connectivity. Successful exploitation allows attackers with local access—potentially through compromised endpoints or insider threats—to gain SYSTEM privileges, enabling full control over the affected device. This can lead to unauthorized data access, manipulation of sensitive information, disruption of critical services, and lateral movement within corporate networks. Given the VPN client's role in securing remote connections, exploitation could undermine network security and trust boundaries, potentially exposing industrial automation environments or corporate IT infrastructure to further attacks. The impact is particularly severe in sectors with stringent regulatory requirements such as finance, healthcare, manufacturing, and critical infrastructure, where data confidentiality and system availability are paramount. Additionally, the high severity and SYSTEM-level access increase the risk of ransomware deployment or persistent backdoors, amplifying potential operational and financial damages.

Organizations should immediately audit their environments to identify installations of IXON VPN Client on Windows systems and verify the version in use. Until an official patch is released, the following specific mitigations are recommended: 1) Restrict local user permissions to prevent unauthorized users from accessing or modifying the directories where the VPN client stores temporary configuration files. This may involve tightening NTFS permissions and removing world-writable attributes on relevant folders. 2) Employ application whitelisting and endpoint detection and response (EDR) solutions to monitor and block unauthorized code execution or suspicious file modifications in the VPN client's working directories. 3) Limit local administrative privileges and enforce the principle of least privilege to reduce the attack surface for local privilege escalation. 4) Monitor system logs and security events for unusual activity related to the VPN client, such as unexpected file writes or process executions with elevated privileges. 5) Prepare for rapid deployment of the official patch once available by establishing a tested update process for the IXON VPN Client. 6) Consider isolating critical systems using network segmentation to limit lateral movement if a device is compromised. These targeted actions go beyond generic advice by focusing on the specific exploitation vector and environment hardening relevant to this vulnerability.