CVE-2025-52461 is a high-severity vulnerability classified as an out-of-bounds read (CWE-125) in the Nex parsing functionality of The Biosig Project's libbiosig library, specifically versions 3.9.0 and the Master Branch (commit 35a819fa). Libbiosig is an open-source library used for reading and writing various biosignal data formats, including the .nex file format. The vulnerability arises when the library processes a specially crafted .nex file, leading to an out-of-bounds read condition. This flaw allows an attacker to read memory beyond the intended buffer boundaries, potentially leaking sensitive information from the process memory space. The vulnerability does not require any privileges or user interaction and can be triggered remotely by supplying a malicious .nex file to an application using the affected libbiosig versions. The CVSS v3.1 score of 8.2 reflects the network attack vector, low attack complexity, no privileges required, no user interaction, unchanged scope, partial confidentiality impact (information leak), no integrity impact, and high availability impact (likely due to potential crashes or denial of service). Although no known exploits are currently reported in the wild, the nature of the vulnerability makes it a significant risk for applications relying on libbiosig for biosignal data processing, especially in environments where untrusted .nex files might be ingested.

For European organizations, the impact of CVE-2025-52461 can be substantial, particularly in sectors relying on biosignal data analysis such as healthcare, biomedical research, and neurotechnology. An information leak could expose sensitive patient or research data, violating data protection regulations like GDPR. Additionally, the high availability impact suggests potential denial-of-service conditions, which could disrupt critical medical devices or research workflows. Organizations processing biosignal data from external sources or collaborating internationally are at risk if they use vulnerable libbiosig versions. The confidentiality breach could lead to exposure of proprietary research or personal health information, resulting in reputational damage, regulatory penalties, and operational disruptions. Given the specialized nature of the library, the threat is more acute for institutions integrating biosignal analysis into their systems, including hospitals, universities, and biotech firms across Europe.

To mitigate this vulnerability, European organizations should immediately audit their software stacks to identify any usage of libbiosig versions 3.9.0 or the affected master branch. Where possible, upgrade to a patched version once released by The Biosig Project. In the interim, implement strict input validation and sandboxing for any application components that process .nex files, restricting file sources to trusted entities only. Employ runtime protections such as AddressSanitizer or similar memory safety tools during development and testing to detect out-of-bounds reads. Network-level controls should be applied to limit exposure to untrusted file uploads or transmissions. Additionally, monitor application logs for crashes or abnormal behavior indicative of exploitation attempts. For critical environments, consider isolating biosignal processing workflows to minimize potential impact. Finally, maintain up-to-date incident response plans tailored to handle data leakage and denial-of-service scenarios stemming from this vulnerability.