CVE-2025-55131 is a vulnerability in Node.js's buffer allocation mechanism, specifically when using the vm module with the timeout option enabled. The flaw arises because buffer allocations (e.g., Buffer.alloc and TypedArray instances like Uint8Array) can be interrupted by the timeout, causing buffers to contain uninitialized memory from previous operations. This uninitialized memory may include sensitive data such as authentication tokens, passwords, or other secrets residing in process memory. The vulnerability requires precise timing to exploit, as the attacker must trigger buffer allocation interruptions and read the leftover data before it is overwritten. While typically exploitation requires in-process code execution, scenarios where untrusted input influences the workload and timeout duration can potentially allow remote exploitation. The vulnerability affects a wide range of Node.js versions, from early versions (4.0) through recent releases (up to 25.2.1). The CVSS 3.0 score of 7.1 reflects a high severity, with network attack vector, high impact on confidentiality and integrity, low privileges required, and no user interaction needed. Although no known exploits are currently reported in the wild, the vulnerability poses a significant risk to applications relying on Node.js for server-side JavaScript execution, especially those using the vm module with timeouts and handling sensitive data in memory buffers.

For European organizations, this vulnerability can lead to leakage of sensitive information such as authentication tokens, passwords, or cryptographic keys, compromising confidentiality. Data integrity may also be affected if corrupted buffers cause application logic errors or data corruption. Organizations running Node.js applications that utilize the vm module with timeout options, particularly in multi-tenant or cloud environments processing untrusted input, face increased risk. The exposure of secrets could facilitate further attacks such as privilege escalation, lateral movement, or data breaches. Given Node.js's widespread use in web services, APIs, and microservices across Europe, the vulnerability could impact sectors including finance, healthcare, government, and technology. The potential for remote exploitation under certain conditions increases the threat surface. Although no exploits are currently known, the high severity and broad version impact necessitate prompt attention to prevent compromise.

1. Upgrade Node.js to the latest patched versions once official fixes are released, as the vulnerability affects many versions including recent ones. 2. Audit and review all uses of the vm module with timeout options in your codebase; avoid or limit use of timeouts where possible to reduce risk. 3. Implement strict input validation and sanitization to minimize untrusted input influencing workload or timeout behavior. 4. Avoid storing sensitive data in memory buffers that could be exposed; use secure memory handling practices and clear buffers immediately after use. 5. Employ runtime application self-protection (RASP) or memory scanning tools to detect anomalous buffer contents or memory leaks. 6. Monitor application logs and network traffic for unusual behavior indicative of exploitation attempts. 7. Consider isolating critical Node.js processes or using containerization to limit impact scope. 8. Stay informed on vendor advisories and apply security patches promptly.