# CVE-2026-83977: Microsoft Windows Biometric Service heap buffer overflow

Source: https://junglewise.ai/threats/cve-2026-83977-microsoft-windows-biometric-service-heap-buffer-overflow  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-09-08. Updated: 2026-09-26  
License: CC BY 4.0 with a link back

CVE-2026-83977 · Severity: high · CVSS 7.8 · Published 2026-09-08

Windows Biometric Service, a system component that processes fingerprint and other biometric authentication data, contains a heap-based buffer overflow vulnerability. An authorized local user can exploit this flaw to execute arbitrary code with elevated system privileges, potentially compromising the entire system.

Technologies: [Microsoft Windows Biometric Service](https://junglewise.ai/threats/technologies/windows-biometric-service). Vendors: [Microsoft](https://junglewise.ai/threats/vendors/microsoft).

## Quick answers

**Is CVE-2026-83977 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-83977 being exploited in the wild.

**How severe is CVE-2026-83977?** High severity, with a CVSS score of 7.8, published 8 September 2026.

**Which products and versions are affected?** Microsoft Windows Biometric Service <UNKNOWN>.

**Is there a fix for CVE-2026-83977?** No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

**How is CVE-2026-83977 attacked?** It is attacked with local access.

**Am I affected by CVE-2026-83977?** Check whether you run Microsoft Windows Biometric Service at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Technical details

A heap-based buffer overflow exists in the Windows Biometric Service that allows an authenticated local attacker to write beyond allocated memory boundaries. The vulnerability requires local access and prior authentication, but does not require user interaction. Successful exploitation enables privilege escalation from a standard user context to SYSTEM or Administrator level, granting complete control over the affected system. A patch is available from Microsoft.

## Affected products

- Microsoft Windows Biometric Service <UNKNOWN>

## Timeline

- 2026-09-08: disclosed

## References

- [https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-83977](https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-83977)

## Related threats

- [Microsoft Windows Biometric Service heap buffer overflow](https://junglewise.ai/threats/cve-2026-83988-microsoft-windows-biometric-service-heap-buffer-overflow)
- [Microsoft Windows Biometric Service heap buffer overflow privilege escalation](https://junglewise.ai/threats/cve-2026-83987-microsoft-windows-biometric-service-heap-buffer-overflow)
- [Microsoft Windows Biometric Service heap buffer overflow](https://junglewise.ai/threats/cve-2026-83985-microsoft-windows-biometric-service-heap-buffer-overflow)
- [Microsoft Windows Biometric Service heap buffer overflow](https://junglewise.ai/threats/cve-2026-83981-microsoft-windows-biometric-service-heap-buffer-overflow)
- [Microsoft Windows Biometric Service heap-based buffer overflow](https://junglewise.ai/threats/cve-2026-83980-microsoft-windows-biometric-service-heap-based-buffer-overflow)