CVE-2025-52581: An integer overflow vulnerability exists in the GDF parsing functionality of The Biosig Project libbiosig 3.9.

This week

CRITICAL 9.8REMOTEDOWNGRADE

CVE-2025-52581 is a critical-severity flaw (CVSS 9.8) affecting libbiosig. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

An integer overflow vulnerability exists in the GDF parsing functionality of The Biosig Project libbiosig 3.9.0 and Master Branch (35a819fa). A specially crafted GDF file can lead to arbitrary code execution. An attacker can provide a malicious file to trigger this vulnerability.

Why this priority

Critical severity
Public exploit reference
Remotely exploitable, no login, no user action

No fix is published yet: follow the downgrade or mitigation steps.

Risk facts

CVSS score	9.8 (Critical)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	0.7% (top 48%)
CISA exploited list	No
Weakness	CWE-190
Published	2025-08-25
Last modified	2026-06-17

Publisher (CNA): Talos · Vendor: libbiosig project

Last updated 2026-06-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2025-08-25 14:15 UTCPublished CVE record published
2026-06-17 09:36 UTCUpdated Record last modified

libbiosig project libbiosig DOWNGRADE

Affected: 3.9.0

Fixed in: no fixed release known

Safe to downgrade to: a release before 3.9.0

1. Check installed version

apt-cache policy libbiosig || rpm -q libbiosig || libbiosig --version

2. No fixed release: DOWNGRADE to a release before 3.9.0 (Debian / Ubuntu)

apt-cache madison libbiosig sudo apt install libbiosig=<VERSION_BEFORE_3.9.0> sudo apt-mark hold libbiosig

2. No fixed release: DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list libbiosig sudo dnf downgrade libbiosig-<VERSION_BEFORE_3.9.0> sudo dnf versionlock add libbiosig

Downgrade risk

Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.

After downgrade

Restart the service, and keep the package held until a fixed release ships.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2025-52581?

libbiosig: downgrade or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2025-52581 being exploited?

CVE-2025-52581 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2025-52581 affect?

CVE-2025-52581 affects libbiosig. Severity is critical (CVSS 9.8). An integer overflow vulnerability exists in the GDF parsing functionality of The Biosig Project libbiosig 3.9.0 and Master Branch (35a819fa). A specially crafted GDF file can lead to arbitrary code execution. An attacker can provide a malic

How urgent is CVE-2025-52581?

Priority 57/100. Critical severity; Public exploit reference; Remotely exploitable, no login, no user action

Related CVEs

CVE-2026-22891 CRITICAL 9.8 DOWNGRADE A heap-based buffer overflow vulnerability exists in the Intan CLP parsing functionality of The Biosig Project
CVE-2026-20777 HIGH 8.1 DOWNGRADE A heap-based buffer overflow vulnerability exists in the Nicolet WFT parsing functionality of The Biosig Proje
CVE-2025-64736 MEDIUM 6.1 DOWNGRADE An out-of-bounds read vulnerability exists in the ABF parsing functionality of The Biosig Project libbiosig 3.
CVE-2025-54494 CRITICAL 9.8 UPGRADE A stack-based buffer overflow vulnerability exists in the MFER parsing functionality of The Biosig Project lib
CVE-2025-54493 CRITICAL 9.8 UPGRADE A stack-based buffer overflow vulnerability exists in the MFER parsing functionality of The Biosig Project lib

References

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