# CVE-2026-85880: Heap-based buffer overflow in Windows ALPC allows an authorized attacker to elevate privileges locally.

Source: https://junglewise.ai/threats/cve-2026-85880-microsoft-windows-heap-based-buffer-overflow-in-advanced-local  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-09-08. Updated: 2026-09-24  
License: CC BY 4.0 with a link back

CVE-2026-85880 · Severity: critical · CVSS 7.8 · Exploited in the wild · Published 2026-09-08

Windows Advanced Local Procedure Call (a core component of Windows used for inter-process communication) contains a heap memory overflow flaw that allows a local attacker to gain system-level privileges. This vulnerability is actively being exploited by attackers in the wild, making immediate patching essential to prevent unauthorized access and control of affected machines.

Technologies: [Microsoft Windows](https://junglewise.ai/threats/technologies/windows). Vendors: [Microsoft](https://junglewise.ai/threats/vendors/microsoft).

## Quick answers

**Is CVE-2026-85880 exploited in the wild?** Yes. CVE-2026-85880 is known to be exploited in the wild, first recorded on 8 September 2026. Treat it as urgent.

**How severe is CVE-2026-85880?** Critical severity, with a CVSS score of 7.8, published 8 September 2026.

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

**Is there a fix for CVE-2026-85880?** 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-2026-85880 attacked?** It is attacked with local access, in an operating system.

**Am I affected by CVE-2026-85880?** Check whether you run Microsoft Windows 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 Microsoft Windows Advanced Local Procedure Call (ALPC), a kernel-mode inter-process communication mechanism. The vulnerability allows a local attacker to overflow a heap buffer, potentially enabling arbitrary code execution with elevated privileges. The attack requires local access to the system but does not require user interaction or special privileges as a precondition. An attacker can exploit this flaw to achieve kernel-level code execution, leading to complete system compromise. The vulnerability is known to be actively exploited in the wild as of the publication date.

## Affected products

- Microsoft Windows <UNKNOWN>

## Timeline

- 2026-09-08: disclosed
- exploited: Known to be exploited in the wild

## Related threats

- [Windows BitLocker heap buffer overflow with physical attack](https://junglewise.ai/threats/cve-2026-97015-heap-based-buffer-overflow-in-windows-bitlocker-allows-an)
- [Microsoft Windows Shell type confusion privilege elevation](https://junglewise.ai/threats/cve-2026-97013-access-of-resource-using-incompatible-type-type-confusion-in)
- [Microsoft Windows VMSwitch out-of-bounds read privilege escalation](https://junglewise.ai/threats/cve-2026-97002-out-of-bounds-read-in-windows-vmswitch-allows-an-authorized)
- [Microsoft Windows USM Communication Manager null pointer dereference](https://junglewise.ai/threats/cve-2026-97000-null-pointer-dereference-in-windows-usm-communication-manager)
- [Microsoft Windows Winsock use after free privilege escalation](https://junglewise.ai/threats/cve-2026-96994-use-after-free-in-winsock-allows-an-authorized-attacker-to)