CVE-2025-54493 is a stack-based buffer overflow vulnerability identified in The Biosig Project's libbiosig library, specifically affecting version 3.9.0 and the master branch (commit 35a819fa). The vulnerability resides in the MFER file parsing code, particularly when handling tag 131 (0x83), which corresponds to the 'Patient Age' field. The flawed code fails to properly validate the length of the input data, leading to a buffer overflow on the stack. This overflow can be exploited by an attacker supplying a maliciously crafted MFER file, enabling arbitrary code execution within the context of the vulnerable application. The vulnerability is severe, with a CVSS v3.1 base score of 9.8, reflecting its network attack vector (AV:N), low attack complexity (AC:L), no privileges required (PR:N), no user interaction (UI:N), and high impact on confidentiality, integrity, and availability (C:H/I:H/A:H). The vulnerability was reserved on July 23, 2025, and published on August 25, 2025. No public patches or known exploits have been reported yet. The vulnerability is classified under CWE-121, indicating a classic stack-based buffer overflow. Given libbiosig's role in processing biosignal data, this vulnerability poses a significant risk to applications relying on it for medical or research purposes.

The impact of CVE-2025-54493 on European organizations is substantial, particularly for those in healthcare, biomedical research, and related industries that utilize libbiosig for biosignal data processing. Successful exploitation allows remote attackers to execute arbitrary code without authentication or user interaction, potentially leading to full system compromise. This can result in unauthorized access to sensitive patient data, manipulation or destruction of medical records, disruption of critical healthcare services, and undermining of research data integrity. The availability of affected systems could be severely impacted, causing operational downtime and jeopardizing patient safety. Furthermore, regulatory compliance risks arise under GDPR due to potential data breaches. The absence of known exploits currently provides a window for proactive mitigation, but the critical severity demands urgent attention to prevent exploitation in the wild.

To mitigate CVE-2025-54493, European organizations should: 1) Monitor The Biosig Project repositories and security advisories closely for official patches or updates addressing this vulnerability and apply them immediately upon release. 2) Implement strict input validation and sanitization for all MFER files processed by libbiosig, rejecting files with unexpected tag lengths or malformed data. 3) Employ application-level sandboxing or containerization to isolate the libbiosig processing environment, limiting the impact of potential exploitation. 4) Conduct code audits and static analysis on any custom integrations of libbiosig to identify and remediate unsafe handling of biosignal data. 5) Restrict network exposure of services processing MFER files to trusted sources only, minimizing attack surface. 6) Maintain up-to-date intrusion detection and prevention systems capable of recognizing anomalous activity related to malformed MFER files. 7) Educate developers and security teams about this vulnerability to ensure rapid response and remediation. These targeted actions go beyond generic advice and address the specific nature of the vulnerability and its exploitation vector.