# CVE-2026-83969: Microsoft Windows Biometric Service heap buffer overflow

Source: https://junglewise.ai/threats/cve-2026-83969-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-2026-83969 · Severity: high · CVSS 7.8 · Published 2026-09-08

Windows Biometric Service is a core operating system component that handles fingerprint, iris, and facial recognition authentication on Windows systems. A heap-based buffer overflow vulnerability allows an attacker with local access and existing system privileges to crash the service or execute arbitrary code with elevated permissions, potentially compromising system security and sensitive biometric data.

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-2026-83969 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-83969 being exploited in the wild.

**How severe is CVE-2026-83969?** 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-2026-83969?** 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-2026-83969 attacked?** It is attacked with local access.

**Am I affected by CVE-2026-83969?** 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 Windows Biometric Service that can be triggered by an authenticated local attacker. The vulnerability occurs due to improper bounds checking when processing biometric data, allowing an attacker to write beyond allocated buffer boundaries. Exploitation requires local access and existing authentication credentials. Successful exploitation enables privilege escalation to SYSTEM level, granting full control over the affected machine. A patch is expected to be available through Microsoft's monthly security update cycle.

## Affected products

- Microsoft Windows Biometric Service <UNKNOWN>

## Timeline

- 2026-09-08: disclosed

## References

- [https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-83969](https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-83969)

## 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)