# CVE-2026-85871: Windows Kernel-Mode Drivers heap-based buffer overflow

Source: https://junglewise.ai/threats/cve-2026-85871-heap-based-buffer-overflow-in-windows-kernel-mode-drivers-allows  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-10-13. Updated: 2026-10-16  
License: CC BY 4.0 with a link back

CVE-2026-85871 · Severity: high · CVSS 7.8 · Published 2026-10-13

A heap buffer overflow vulnerability in Windows kernel drivers allows an authorized local user to corrupt memory and gain elevated system privileges. An attacker with legitimate access to the system could exploit this to run code with kernel-level permissions, bypassing security controls and compromising system integrity.

Technologies: [Microsoft Windows Kernel-Mode Drivers](https://junglewise.ai/threats/technologies/windows-kernel-mode-drivers). Vendors: [Microsoft](https://junglewise.ai/threats/vendors/microsoft).

## Quick answers

**Is CVE-2026-85871 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-85871 being exploited in the wild.

**How severe is CVE-2026-85871?** High severity, with a CVSS score of 7.8, published 13 October 2026.

**Which products and versions are affected?** Microsoft Windows Kernel-Mode Drivers.

**Is there a fix for CVE-2026-85871?** 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-2026-85871 attacked?** It is attacked with local access, in an operating system.

**Am I affected by CVE-2026-85871?** Check whether you run Microsoft Windows Kernel-Mode Drivers. 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 Kernel-Mode Drivers that can be triggered by an authorized local attacker to overwrite heap memory and achieve privilege escalation. The vulnerability requires prior authentication or user interaction on the target system. Exploitation grants kernel-mode execution capability.

## Affected products

- Microsoft Windows Kernel-Mode Drivers

## Timeline

- 2026-10-13: disclosed

## References

- [https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-85871](https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-85871)

## Related threats

- [Microsoft Windows Kernel-Mode Drivers type confusion privilege escalation](https://junglewise.ai/threats/cve-2026-45600-microsoft-windows-kernel-mode-drivers-type-confusion-privilege)
- [Microsoft Windows use after free in Kernel-Mode Drivers](https://junglewise.ai/threats/cve-2026-34332-microsoft-windows-use-after-free-in-kernel-mode-drivers)