CVE-2025-54485VulnerabilityPublished 25 Aug 2025Updated 3 Nov 2025

CVE-2025-54485: 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, 06:26 UTC

CVSS 3.1 base score

9.8Critical

How severe the flaw is on the 0–10 CVSS scale.

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:H

Attack Vector: Network
Attack Complexity: Low
Privileges Required: None
User Interaction: None
Scope: Unchanged
Confidentiality: High
Integrity: High
Availability: High

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Network: The vulnerable component is bound to the network stack and the set of possible attackers extends beyond the other options listed, up to and including the entire Internet. Such a vulnerability is often termed 'remotely exploitable' and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
Attack Complexity: Low: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
Privileges Required: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files to carry out an attack.
User Interaction: None: The vulnerable system can be exploited without any interaction from any user.
Scope: Unchanged: An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority.
Confidentiality: High: There is total loss of confidentiality, resulting in all resources within the impacted component being divulged to the attacker. Alternatively, access to only some restricted information is obtained, but the disclosed information presents a direct, serious impact.
Integrity: High: There is a total loss of integrity, or a complete loss of protection. For example, the attacker is able to modify any/all files protected by the impacted component. Alternatively, only some files can be modified, but malicious modification would present a direct, serious consequence to the impacted component.
Availability: High: There is total loss of availability, resulting in the attacker being able to fully deny access to resources in the impacted component; this loss is either sustained (while the attacker continues to deliver the attack) or persistent (the condition persists even after the attack has completed). Alternatively, the attacker has the ability to deny some availability, but the loss of availability presents a direct, serious consequence to the impacted component (e.g., the attacker cannot disrupt existing connections, but can prevent new connections; the attacker can repeatedly exploit a vulnerability that, in each instance of a successful attack, leaks a only small amount of memory, but after repeated exploitation causes a service to become completely unavailable).

Definitions: FIRST CVSS v3.1 specification.

Exploitation 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 2026-10-26.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Affected software

Product	Affected	Fixed in
The Biosig Project libbiosig	Affected =3.9.0	Fixed in–

AI-suggested

1. Monitor The Biosig Project repositories and security advisories closely for official patches addressing CVE-2025-54485 and apply them immediately upon release. 2. Until patches are available, implement strict input validation and sanitization on all MFER files before processing to detect and reject malformed or suspicious files, especially those with tag 8 length fields exceeding expected values. 3. Employ sandboxing or containerization techniques to isolate the libbiosig processing environment, limiting the impact of potential exploitation. 4. Restrict access to systems processing MFER files to trusted sources and networks, reducing exposure to malicious inputs. 5. Conduct code audits and static analysis on any custom or third-party software integrating libbiosig to identify and remediate unsafe usage patterns. 6. Enhance monitoring and logging around file ingestion points to detect anomalous activity or crashes indicative of exploitation attempts. 7. Educate staff handling biomedical data about the risks of processing untrusted files and enforce strict operational security policies. 8. Consider alternative libraries or tools with no known vulnerabilities for MFER parsing if immediate patching is not feasible.

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 8785 of biosig.c on the current master branch (35a819fa), when the Tag is 8: else if (tag==8) { if (len>2) fprintf(stderr,"Warning MFER tag8 incorrect length %i>2\n",len); curPos += ifread(buf,1,len,hdr);

Impact

For European organizations, the impact of CVE-2025-54485 is significant, especially in sectors relying on biomedical signal processing such as hospitals, research institutions, and medical device manufacturers. Exploitation could lead to unauthorized code execution within critical systems, potentially compromising patient data confidentiality, altering medical data integrity, or causing denial of service in diagnostic tools. This could disrupt healthcare delivery and research activities, leading to financial losses, regulatory penalties under GDPR, and reputational damage. The vulnerability's remote exploitability without authentication increases the attack surface, particularly for organizations that process MFER files from external sources or third-party vendors. Additionally, the criticality of healthcare infrastructure in Europe makes this vulnerability a potential target for cyber espionage or sabotage. The lack of known exploits currently provides a window for proactive mitigation, but the high CVSS score demands urgent attention to prevent future attacks.

Summary

CVE-2025-54485 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 is located in the MFER (Medical Format for Electroencephalographic Recordings) file parsing code, particularly when handling tag 8 data. The flaw occurs due to insufficient length validation before reading data into a fixed-size stack buffer, allowing an attacker to overflow the buffer by providing a maliciously crafted MFER file with an incorrect length field. This memory corruption can lead to arbitrary code execution, enabling an attacker to run code with the privileges of the application using libbiosig. The vulnerability is exploitable remotely without authentication or user interaction, as it only requires the processing of a crafted MFER file. The CVSS v3.1 base score is 9.8, reflecting its critical severity with network attack vector, low attack complexity, no privileges required, and no user interaction needed. The vulnerability impacts confidentiality, integrity, and availability, making it a severe threat. Currently, no public patches or known exploits are reported, but the technical details indicate a high risk of exploitation once weaponized. Libbiosig is used primarily in biomedical signal processing applications, including EEG data analysis, which are common in healthcare and research environments. The vulnerability's presence in a widely used open-source library increases the risk of supply chain attacks or indirect exploitation through dependent software.

CWE-121Stack-based Buffer Overflow (opens in a new tab)
Variant weaknessLikelihood of exploit: HighCWE Top 25 (2025): #14
A stack-based buffer overflow condition is a condition where the buffer being overwritten is allocated on the stack (i.e., is a local variable or, rarely, a parameter to a function).
Operation · Build and Compilation · Environment Hardening
Use automatic buffer overflow detection mechanisms that are offered by certain compilers or compiler extensions. Examples include: the Microsoft Visual Studio /GS flag, Fedora/Red Hat FORTIFY_SOURCE GCC flag, StackGuard, and ProPolice, which provide various mechanisms including canary-based detection and range/index…
Architecture and Design
Use an abstraction library to abstract away risky APIs. Not a complete solution.
Implementation
Implement and perform bounds checking on input.
OWASP Cheat Sheets
XML Security (opens in a new tab)
Mass Assignment (opens in a new tab)
OWASP ASVS 4.0.3
V13.3.1 (opens in a new tab)
V5.1.4 (opens in a new tab)
V5.1.3 (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 3 Nov 2025, 19:44 UTC

WeaknessesCWE-121

Technical details

References

Community reviews

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