CVE-2025-49739 is a high-severity vulnerability identified in Microsoft Visual Studio 2017 versions 15.0 through 15.9.0. The vulnerability is classified under CWE-59, which pertains to improper link resolution before file access, commonly known as 'link following'. This flaw allows an unauthorized attacker to exploit the way Visual Studio resolves symbolic links or shortcuts before accessing files, potentially redirecting file operations to unintended locations. As a result, an attacker can perform privilege escalation over a network without requiring prior authentication, leveraging this improper link resolution to gain elevated privileges on the affected system. The CVSS v3.1 score of 8.8 reflects the critical nature of this vulnerability, highlighting its network attack vector, low attack complexity, no privileges required, but requiring user interaction, and its high impact on confidentiality, integrity, and availability. Although no known exploits are currently reported in the wild, the vulnerability's characteristics suggest it could be exploited to compromise development environments, potentially leading to unauthorized code execution, data manipulation, or disruption of development workflows. The lack of available patches at the time of publication increases the urgency for organizations to implement interim mitigations and monitor for updates from Microsoft.

For European organizations, this vulnerability poses significant risks, especially for those relying on Visual Studio 2017 for software development and maintenance. Exploitation could lead to unauthorized privilege escalation within development environments, enabling attackers to alter source code, inject malicious code, or disrupt build processes. This could compromise the integrity of software products, leading to downstream security issues in deployed applications. Confidentiality breaches are also possible if attackers access sensitive project files or intellectual property. The availability of development tools could be impacted, delaying critical software updates or releases. Given the network attack vector and the absence of required privileges, attackers could target exposed development workstations or servers remotely, increasing the threat surface. Organizations involved in critical infrastructure, finance, healthcare, or government sectors in Europe could face heightened risks due to the potential for supply chain compromise or disruption of essential services.

In the absence of an official patch, European organizations should implement several specific mitigations: 1) Restrict network access to development machines running Visual Studio 2017, using network segmentation and firewalls to limit exposure. 2) Enforce strict user privilege management, ensuring developers operate with the least privileges necessary to reduce the impact of potential exploitation. 3) Disable or restrict the use of symbolic links or shortcuts within project directories where feasible, to minimize the risk of link following abuse. 4) Monitor file system activities for unusual link resolution or file access patterns indicative of exploitation attempts. 5) Educate developers and IT staff about the risk and encourage caution when interacting with untrusted files or network shares. 6) Prepare for rapid deployment of patches once Microsoft releases updates by maintaining an up-to-date inventory of affected systems. 7) Employ application whitelisting and endpoint detection and response (EDR) solutions to detect and block suspicious behaviors related to privilege escalation attempts.