CVE-2025-52461 is a high-severity vulnerability identified in The Biosig Project's libbiosig library, specifically affecting versions 3.9.0 and the Master Branch (commit 35a819fa). The vulnerability is classified as CWE-125, an out-of-bounds read, occurring in the Nex file parsing functionality. This flaw allows an attacker to craft a malicious .nex file that, when processed by libbiosig, triggers an out-of-bounds read condition. This can lead to an information leak, exposing potentially sensitive memory contents to the attacker. The vulnerability does not require any privileges or user interaction to be exploited, and it can be triggered remotely simply by processing a maliciously crafted file. The CVSS v3.1 base score of 8.2 reflects the high impact on availability (denial of service or crash) and confidentiality (information disclosure), with low attack complexity and no required privileges or user interaction. The vulnerability does not affect integrity directly. No known exploits are currently in the wild, and no patches have been linked yet, indicating that mitigation may require either vendor updates or user-side workarounds. The Biosig Project's libbiosig is a library used for biosignal processing, often in scientific and medical research contexts, which may process Nex format files containing electrophysiological data. The out-of-bounds read vulnerability could allow attackers to leak sensitive data from memory buffers during parsing, potentially exposing confidential research data or patient information if used in clinical environments.

For European organizations, the impact of CVE-2025-52461 can be significant, especially for research institutions, universities, and healthcare providers that utilize libbiosig for biosignal data analysis. The information leak could expose sensitive patient data or proprietary research information, leading to privacy violations under GDPR and other data protection regulations. Additionally, the vulnerability's ability to cause availability issues (crashes or denial of service) could disrupt critical data processing workflows, impacting operational continuity. Since the vulnerability can be triggered remotely without authentication or user interaction, attackers could exploit it by delivering malicious .nex files via email attachments, file uploads, or shared repositories. This raises concerns for European organizations involved in collaborative research or clinical data exchange. The exposure of sensitive data could result in regulatory fines, reputational damage, and loss of trust. Moreover, the lack of patches at the time of disclosure increases the window of risk for organizations relying on affected libbiosig versions.

To mitigate CVE-2025-52461, European organizations should first identify all instances of libbiosig 3.9.0 and the affected master branch in their environments, particularly within research and healthcare software stacks. Until an official patch is released, organizations should implement strict input validation and sandboxing of any process that parses .nex files to contain potential memory leaks or crashes. Employing file integrity monitoring and restricting the acceptance of .nex files from untrusted sources can reduce exposure. Network-level controls such as email filtering and endpoint protection should be enhanced to detect and block malicious file attachments. Organizations should also monitor vendor communications closely for patches or updates and plan rapid deployment once available. Where possible, isolating biosignal processing systems from critical networks and limiting user privileges can reduce the attack surface. Additionally, conducting internal code reviews or applying temporary source code fixes (e.g., bounds checking) if feasible can provide interim protection. Finally, maintaining comprehensive logging and monitoring for anomalous crashes or memory access errors related to libbiosig processes will aid in early detection of exploitation attempts.