CVE-2025-54486 is a stack-based buffer overflow vulnerability classified under CWE-121, found in the MFER parsing code of The Biosig Project's libbiosig library, specifically in versions 3.9.0 and the master branch (commit 35a819fa). The vulnerability arises in biosig.c at line 8824 during the handling of tag 11 (0x0B) in MFER files, where the length check is insufficient, allowing a specially crafted file to overflow the stack buffer. This overflow can overwrite the return address or other control data, enabling an attacker to execute arbitrary code on the affected system. The vulnerability requires no privileges, no user interaction, and can be exploited remotely by supplying a malicious MFER file to an application that uses libbiosig for biosignal data processing. The CVSS v3.1 base score is 9.8, reflecting critical severity with network attack vector, low attack complexity, no privileges required, and no user interaction needed. The impact covers confidentiality, integrity, and availability, as arbitrary code execution can lead to full system compromise. Currently, no public patches or exploits are reported, but the vulnerability's nature and severity make it a high-risk issue for any environment processing MFER files with libbiosig. The Biosig Project is a library used primarily in biomedical signal processing, which implies that healthcare, research, and related industries are the main users and thus the primary targets. The vulnerability's exploitation could lead to data breaches, system takeovers, or disruption of critical biomedical data processing workflows.

For European organizations, the impact of CVE-2025-54486 is significant, particularly in sectors relying on biosignal processing such as healthcare providers, biomedical research institutions, and medical device manufacturers. Exploitation could lead to unauthorized access to sensitive patient data, manipulation or corruption of biomedical signals, and disruption of diagnostic or monitoring systems. This could result in compromised patient safety, regulatory non-compliance (e.g., GDPR violations), and reputational damage. Additionally, the arbitrary code execution capability could be leveraged to establish persistent footholds within networks, facilitating further attacks such as ransomware or espionage. Given the critical nature of healthcare infrastructure in Europe and the increasing digitization of medical data, this vulnerability poses a substantial risk to operational continuity and data confidentiality. The lack of known exploits currently provides a window for proactive mitigation, but the ease of exploitation and high severity score necessitate urgent action.

1. Monitor The Biosig Project repositories and official channels for patches addressing CVE-2025-54486 and apply them immediately upon release. 2. Until patches are available, restrict or validate all MFER file inputs rigorously, employing file integrity checks and sandboxing to limit exposure. 3. Employ runtime protections such as stack canaries, ASLR (Address Space Layout Randomization), and DEP (Data Execution Prevention) in applications using libbiosig to mitigate exploitation impact. 4. Conduct code audits and static analysis on any custom integrations of libbiosig to identify and remediate unsafe parsing or buffer handling. 5. Implement network-level controls to limit exposure of systems processing MFER files, including segmentation and strict access controls. 6. Train security and IT staff to recognize suspicious MFER files and anomalous application behavior indicative of exploitation attempts. 7. Develop and test incident response plans specific to potential exploitation scenarios involving biosignal processing systems. 8. Engage with vendors and open-source communities to share threat intelligence and coordinate timely remediation efforts.