CVE-2025-53557Public exploitNetwork attack vector

Code execution via unchecked MFER channel index

Published Aug 25, 2025 · Updated Nov 3, 2025

Heap-based buffer overflow in libbiosig 3.9.0 and Master Branch (35a819fa) allows attackers to execute code via a crafted MFER file. The sopen_extended parser uses an attacker-controlled Tag 63 channel number to index hdr->CHANNEL without checking the allocated array size, causing an out-of-bounds heap write. Any application that passes an attacker-supplied MFER file to this parser reaches the write without credentials or user interaction.

CVSS severity9.8
Critical
EPSS probability0.74%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Heap-based buffer overflow in libbiosig 3.9.0 and Master Branch (35a819fa) allows attackers to execute code via a crafted MFER file. The sopen_extended parser uses an attacker-controlled Tag 63 channel number to index hdr->CHANNEL without checking the allocated array size, causing an out-of-bounds heap write. Any application that passes an attacker-supplied MFER file to this parser reaches the write without credentials or user interaction.

The record

CVE
CVE-2025-53557
Published
Aug 25, 2025
Updated
Nov 3, 2025
Vendor
The BioSig Project
Product
libbiosig
Classifications
CWE-122, T1203
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 25, 2025CVE publishedPublication date reported by the CVE source.
  2. Nov 3, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=3.9.0
  2. Affected versionversion=Master Branch (35a819fa)

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

The BioSig Project · libbiosigversion=3.9.0; version=Master Branch (35a819fa)

Published CVSS scores

9.8TalosCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-122Heap-based Buffer Overflow
T1203Exploitation for Client Execution

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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