A stack-based buffer overflow vulnerability exists in the MFER parsing functionality of The Biosig Project libbiosig 3.9.0 and Master Branch (35a819fa). A specially crafted MFER file can lead to arbitrary code execution. An attacker can provide a malicious file to trigger this vulnerability.This vulnerability manifests on line 9141 of biosig.c on the current master branch (35a819fa), when the Tag is 67:

            else if (tag==67)     //0x43: Sample skew
            {
                int skew=0;     // [1]
                curPos += ifread(&skew, 1, len,hdr);

In this case, the address of the newly-defined integer skew [1] is overflowed instead of buf. This means a stack overflow can occur using much smaller values of len in this code path.

References

• https://nvd.nist.gov/vuln/detail/CVE-2025-54492
• https://talosintelligence.com/vulnerability_reports/TALOS-2025-2234