CVE-2025-66046: 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 25 Oct 2026, 19:02 UTC
- EPSS
- 0.5% chance of exploitation in 30 days – higher than 45% 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 11 Dec 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 2026-10-25.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| The Biosig Project libbiosig | Affected
| Fixed in– |
AI-suggested
1. Immediately audit all systems and applications that utilize libbiosig 3.9.1 to identify exposure to MFER file parsing. 2. Implement strict input validation and sanitization for all MFER files, especially scrutinizing Tag 67 data fields to prevent malformed inputs from triggering the overflow. 3. Employ application-layer sandboxing or isolation techniques to limit the impact of potential exploitation. 4. Monitor logs and network traffic for unusual activity related to libbiosig processes or unexpected MFER file handling. 5. Engage with The Biosig Project and relevant vendors to obtain patches or updates as soon as they become available and prioritize their deployment. 6. Consider temporarily disabling or restricting the processing of MFER files from untrusted sources until patches are applied. 7. Incorporate runtime application self-protection (RASP) or exploit mitigation technologies such as stack canaries, DEP, and ASLR if not already enabled. 8. Educate developers and system administrators about this vulnerability to ensure awareness and prompt response.
Description
Several stack-based buffer overflow vulnerabilities exists in the MFER parsing functionality of The Biosig Project libbiosig 3.9.1. A specially crafted MFER file can lead to arbitrary code execution. An attacker can provide a malicious file to trigger these vulnerabilities.When Tag is 67