CVE-2025-46411 is a high-severity stack-based buffer overflow vulnerability identified in The Biosig Project's libbiosig library, specifically in the MFER file parsing functionality. The affected versions include libbiosig 3.9.0 and the Master Branch revision 35a819fa. The vulnerability arises when the library processes specially crafted MFER files, which are used for storing biosignal data such as EEG, ECG, and other physiological signals. Due to improper bounds checking during parsing, an attacker can supply a malicious MFER file that triggers a stack buffer overflow, potentially allowing arbitrary code execution on the host system. The CVSS v3.1 score is 8.1, reflecting a high impact on confidentiality, integrity, and availability, with network attack vector but requiring high attack complexity and no privileges or user interaction. Although no known exploits are currently observed in the wild, the vulnerability poses a significant risk because libbiosig is integrated into various biomedical and research software tools that process biosignal data. Successful exploitation could lead to full system compromise, data theft, or disruption of critical biomedical applications. The vulnerability is categorized under CWE-121, which is a classic stack-based buffer overflow, a well-understood and often exploited class of vulnerabilities. No official patches or fixes have been published yet, increasing the urgency for users to apply mitigations or monitor for updates.

For European organizations, especially those involved in healthcare, biomedical research, and medical device manufacturing, this vulnerability presents a critical risk. Many European hospitals, research institutions, and medical device vendors rely on biosignal processing software that may incorporate libbiosig. Exploitation could lead to unauthorized access to sensitive patient data, manipulation of medical signals, or disruption of diagnostic and monitoring equipment. This could compromise patient safety, violate GDPR regulations regarding personal health data, and cause reputational damage. Additionally, critical infrastructure relying on biosignal analysis for operational monitoring could face availability issues. The high confidentiality, integrity, and availability impact combined with the network attack vector means that remote attackers could exploit this vulnerability without user interaction, increasing the threat surface. The absence of known exploits in the wild currently offers a window for proactive defense, but the potential for rapid weaponization remains.

Given the lack of official patches, European organizations should immediately audit their software supply chains to identify any usage of libbiosig 3.9.0 or the affected master branch. Where possible, disable or restrict the processing of MFER files from untrusted or external sources. Employ application-layer sandboxing or containerization to isolate biosignal processing applications, limiting the impact of potential exploitation. Implement strict network segmentation and firewall rules to reduce exposure of vulnerable systems to untrusted networks. Monitor logs and network traffic for anomalous activity related to MFER file handling. Engage with software vendors and open-source maintainers to prioritize patch development and apply updates promptly once available. Additionally, conduct code reviews and fuzz testing on biosignal parsing components to identify and remediate similar vulnerabilities proactively. For critical systems, consider deploying runtime application self-protection (RASP) or exploit mitigation technologies such as stack canaries, ASLR, and DEP to reduce exploitation success likelihood.