Cyber Posture

CVE-2025-66046

CriticalPublic PoC

Published: 11 December 2025

Published
11 December 2025
Modified
17 December 2025
KEV Added
Patch
CVSS Score 9.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS Score 0.0013 31.8th percentile
Risk Priority 20 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2025-66046 is a critical-severity Stack-based Buffer Overflow (CWE-121) vulnerability in Libbiosig Project Libbiosig. Its CVSS base score is 9.8 (Critical).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked at the 31.8th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.

The strongest mitigations our analysis identified are NIST 800-53 SI-16 (Memory Protection) and SI-2 (Flaw Remediation).

Threat & Defense at a Glance

What attackers do: exploitation maps to Exploit Public-Facing Application (T1190). What defenders deploy: see the NIST 800-53 controls recommended below.
Threat & Defense Details

Mitigating Controls (NIST 800-53 r5)AI

prevent

Directly mitigates the stack-based buffer overflow in libbiosig by requiring timely remediation through patching or upgrading to a non-vulnerable version.

prevent

Implements memory protections such as stack canaries, ASLR, and DEP to prevent arbitrary code execution from stack buffer overflows during MFER parsing.

prevent

Requires validation of MFER file inputs before parsing to reject specially crafted files that trigger the Tag 67 buffer overflow vulnerability.

MITRE ATT&CK Enterprise TechniquesAI

T1190 Exploit Public-Facing Application Initial Access
Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.
Why these techniques?

Remote (AV:N), unauthenticated (PR:N), no-interaction (UI:N) buffer overflow enabling arbitrary code execution via malicious MFER file directly facilitates exploitation of public-facing applications.

Confidence: HIGH · MITRE ATT&CK Enterprise v19.0

NVD 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…

more

is 67

Deeper analysisAI

CVE-2025-66046 involves several stack-based buffer overflow vulnerabilities (CWE-121, CWE-787) in the MFER parsing functionality of The Biosig Project's libbiosig version 3.9.1. These flaws occur specifically when processing Tag 67 in a specially crafted MFER file, which can trigger arbitrary code execution. The vulnerability carries a CVSS v3.1 base score of 9.8, reflecting its critical severity due to network accessibility, low attack complexity, and lack of prerequisites.

An unauthenticated attacker (PR:N) can exploit this remotely (AV:N) with low complexity (AC:L) and no user interaction (UI:N), by providing a malicious MFER file to an application using the affected libbiosig library. Successful exploitation leads to high-impact arbitrary code execution, compromising confidentiality (C:H), integrity (I:H), and availability (A:H) within the unchanged security scope (S:U).

Mitigation details are outlined in the Talos Intelligence advisory at https://talosintelligence.com/vulnerability_reports/TALOS-2025-2296.

Details

CWE(s)

Affected Products

libbiosig project
libbiosig
≤ 3.9.2

CVEs Like This One

CVE-2025-66045Same product: Libbiosig Project Libbiosig
CVE-2025-66044Same product: Libbiosig Project Libbiosig
CVE-2025-66043Same product: Libbiosig Project Libbiosig
CVE-2025-66047Same product: Libbiosig Project Libbiosig
CVE-2025-54488Same product: Libbiosig Project Libbiosig
CVE-2025-54492Same product: Libbiosig Project Libbiosig
CVE-2025-54489Same product: Libbiosig Project Libbiosig
CVE-2025-54491Same product: Libbiosig Project Libbiosig
CVE-2025-54494Same product: Libbiosig Project Libbiosig
CVE-2025-54490Same product: Libbiosig Project Libbiosig

References