CVE-2025-6075 identifies a vulnerability in the CPython implementation maintained by the Python Software Foundation. The issue arises specifically in the os.path.expandvars() function, which expands environment variables in a given string. If the input to this function is controlled by an attacker or untrusted user, it can cause performance degradation during the expansion process. This is likely due to inefficient handling or repeated processing of environment variables, which can lead to excessive CPU usage or delays. The vulnerability does not allow for code execution, privilege escalation, or data leakage, but it can degrade the performance of applications relying on this function. The CVSS 4.0 score of 1.8 reflects the low impact and difficulty of exploitation, requiring local access with high privileges and no user interaction. No patches or known exploits are currently available, indicating the issue is either newly discovered or not widely exploited. The vulnerability is relevant for any software or systems using CPython where environment variable expansion is performed on user-controlled input, which could include automation scripts, web applications, or development tools.

For European organizations, the primary impact of CVE-2025-6075 is potential performance degradation in Python-based applications that use os.path.expandvars() with untrusted input. This could lead to slower response times, increased resource consumption, and reduced efficiency in critical systems, especially in environments with high volumes of environment variable expansions. While the vulnerability does not compromise data confidentiality or integrity, degraded performance can affect service availability indirectly by causing delays or timeouts. Organizations relying heavily on Python for automation, data processing, or web services might experience operational inefficiencies. However, given the low severity and requirement for local high-privilege access, the overall risk is limited. The absence of known exploits reduces immediate threat levels but does not eliminate the need for vigilance.

To mitigate this vulnerability, European organizations should audit their Python codebases and scripts to identify any usage of os.path.expandvars() where input could be influenced by untrusted users. Avoid passing user-controlled data directly to this function. Implement strict input validation and sanitization to ensure only expected environment variable names or safe strings are expanded. Consider refactoring code to limit environment variable expansion or replace expandvars() with safer alternatives when possible. Monitor system performance for unusual CPU or memory usage patterns that could indicate exploitation attempts. Keep Python installations up to date and watch for official patches or updates from the Python Software Foundation addressing this issue. Additionally, enforce the principle of least privilege to limit local high-privilege access, reducing the risk of exploitation.