# CVE-2026-72991: Microsoft Windows Biometric Service heap buffer overflow

Source: https://junglewise.ai/threats/cve-2026-72991-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-2026-72991 · Severity: high · CVSS 7.8 · Published 2026-09-08

Windows Biometric Service is a system component that manages fingerprint and iris scanning on Windows devices. A heap buffer overflow in this service allows an authorized local user to execute arbitrary code with elevated privileges, potentially enabling takeover of the affected 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-2026-72991 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-72991 being exploited in the wild.

**How severe is CVE-2026-72991?** High severity, with a CVSS score of 7.8, published 8 September 2026.

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

**Is there a fix for CVE-2026-72991?** 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-2026-72991 attacked?** It is attacked with local access, in a hosted service.

**Am I affected by CVE-2026-72991?** Check whether you run Microsoft Windows Biometric Service. 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, a privileged system component responsible for biometric authentication. The vulnerability is triggered when processing malformed input during local operations. An attacker with local access and authorization to interact with the biometric service can overflow a heap buffer to corrupt memory and escalate privileges to SYSTEM level. The attack requires local access and prior authorization but does not require user interaction or network connectivity. A patch is available from Microsoft.

## Affected products

- Microsoft Windows Biometric Service

## Timeline

- 2026-09-08: disclosed

## References

- [https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-72991](https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-72991)

## 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)