CVE-2025-54492: The Biosig Project libbiosig · Stack-based Buffer Overflow
Affects The Biosig Project libbiosigSource CVE Database V5
Not known to be exploited · CVSS 9.8 Critical.
Data as of 26 Oct 2026, 08:30 UTC
- EPSS
- 0.6% chance of exploitation in 30 days – higher than 52% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 25 Aug 2025
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| The Biosig Project libbiosig | Affected
| Fixed in– |
AI-suggested
To mitigate CVE-2025-54492, European organizations should immediately audit their software stacks to identify any usage of libbiosig version 3.9.0 or the affected master branch. Since no official patches are currently available, organizations should consider the following specific actions: 1) Temporarily disable or isolate components that process MFER files using libbiosig until a patch is released. 2) Implement strict input validation and sandboxing around any functionality that parses MFER files to contain potential exploitation attempts. 3) Monitor network and system logs for anomalous activity related to MFER file processing, including unexpected crashes or memory errors. 4) Engage with The Biosig Project community or maintainers to obtain or contribute patches addressing the vulnerability. 5) For developers, review and refactor the parsing code to include proper bounds checking on the 'len' parameter and avoid stack variable overflow. 6) Employ runtime protections such as stack canaries, DEP (Data Execution Prevention), and ASLR (Address Space Layout Randomization) to reduce exploitation success. 7) Educate staff about the risks of processing untrusted biosignal files and enforce strict file provenance policies. These targeted measures go beyond generic advice by focusing on the specific vulnerable code path and operational context.
Description
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.