CVE-2026-20777

A heap-based buffer overflow vulnerability exists in the Nicolet WFT parsing functionality of The...

8.1 HighFix available

A heap-based buffer overflow vulnerability exists in the Nicolet WFT parsing functionality of The Biosig Project libbiosig 3.9.2 and Master Branch (db9a9a63). A specially crafted .wft file can lead to arbitrary code execution. An attacker can provide a malicious file to trigger this vulnerability.

Attack profile

How easy it is to exploit

Attack vector: Network
Complexity: High
Privileges needed: None
User interaction: None

What an attacker can affect

Confidentiality: High
Integrity: High
Availability: High

Exploit likelihood

0.59%Up 0.5 points since Mar 4, 2026

What each source reports

CVE List Score used 8.1

Record: CVE-2026-20777
CVSS 3.1: 8.1 HighCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
Weakness: CWE-122
Updated: 2026-11-02

EUVDEUVD-2026-9291 8.1

Record: EUVD-2026-9291
CVSS 3.1: 8.1 HighCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
Updated: 2026-11-02

GitHub AdvisoriesGHSA-2gq5-x5qp-v68m 8.1

A heap-based buffer overflow vulnerability exists in the Nicolet WFT parsing functionality of The...

Record: GHSA-2gq5-x5qp-v68m
CVSS 3.1: 8.1 HighCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
Weakness: CWE-122
Updated: 2026-11-02

NVD 8.1

Record: CVE-2026-20777
CVSS 3.1: 8.1 HighCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
Weakness: CWE-122
Updated: 2026-11-02

OSV 8.1

Record: CVE-2026-20777
CVSS 3.1: 8.1 HighCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
Updated: 2026-11-02

OSVDEBIAN-CVE-2026-20777 8.1

Record: DEBIAN-CVE-2026-20777
CVSS 3.1: 8.1 HighCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
Updated: 2026-11-02

OSVUBUNTU-CVE-2026-20777 8.1

Record: UBUNTU-CVE-2026-20777
CVSS 3.1: 8.1 HighCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
Updated: 2026-11-02

OSVUSN-8713-1 No score

biosig vulnerabilities

Mark Bereza and Lilith Wyatt discovered that BioSig incorrectly handled certain crafted input files. An attacker could possibly use this issue to cause a denial of service or execute arbitrary code. (CVE-2026-22891, CVE-2026-20777)

Record: USN-8713-1
Updated: 2026-11-02

Affected products

Affected packages

Affected packages
Package	Affected	Fixed
`biosig` Debian:12	All versions, plus listed versions 2.5.0-12.5.2-12.5.2-22.6.0-12.6.1-13.9.0-13.9.5-1	None known
`biosig` Debian:13	All versions, plus listed versions 3.9.0-13.9.5-1	None known
`biosig` Debian:14	before 3.9.5-1, plus listed versions 3.9.0-1	3.9.5-1
`biosig` Ubuntu:Pro:24.04:LTS	before 2.6.0-1ubuntu1+esm1, plus listed versions 2.5.0-1build22.5.2-12.5.2-1build12.5.2-22.6.0-12.6.0-1build12.6.0-1ubuntu1	2.6.0-1ubuntu1+esm1
`biosig` Ubuntu:25.10	All versions, plus listed versions 2.6.1-1build33.9.0-1	None known
`biosig` Ubuntu:Pro:26.04:LTS	before 3.9.0-1ubuntu0.1~esm1, plus listed versions 3.9.0-13.9.0-1build13.9.0-1build23.9.0-1build3	3.9.0-1ubuntu0.1~esm1
`biosig` Ubuntu:Pro:22.04:LTS	before 2.3.3-1ubuntu0.1~esm1, plus listed versions 2.1.2-42.1.2-4build12.1.2-4build22.3.3-12.3.3-1build12.3.3-1build2	2.3.3-1ubuntu0.1~esm1

History

History
Recorded	Changed	Sources
Nov 2, 2026	aliases, published	EUVD
Nov 2, 2026	first indexed	CVE List, GitHub Advisories, NVD, OSV

Dates are when Every CVE recorded each change. Upstream dates may differ.

In short

CVE-2026-20777 is a high vulnerability (CVSS 8.1) in Libbiosig Project Libbiosig, published March 3, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.59%, the 48th percentile. Fixed in biosig 3.9.5-1.