CVE-2026-85880 Windows Advanced Local Procedure Call (ALPC) Elevation of Privilege Vulnerability

Api.Msrc.Microsoft • September 8, 2026

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Released: Sep 8, 2026

CWE-122: Heap-based Buffer Overflow

CWE-908: Use of Uninitialized Resource

Please see Common Vulnerability Scoring System for more information on the definition of these metrics.

Heap-based buffer overflow in Windows ALPC allows an authorized attacker to elevate privileges locally.

The following table provides an exploitability assessment for this vulnerability at the time of original publication.

What privileges could be gained by an attacker who successfully exploited this vulnerability?

An attacker who successfully exploited this vulnerability could gain SYSTEM privileges.

How could an attacker exploit this vulnerability?

An attacker who can execute code in a low-privilege AppContainer could exploit this vulnerability locally to escape the sandbox and elevate privileges on the affected system. No additional user interaction is required.

Volexity with

, and with Proofpoint Inc.

To determine the support lifecycle for your software, see the Microsoft Support Lifecycle .

Information published.

The full story

This article is one source in a clustered incident — the cluster page carries the summary, timeline and every other outlet covering it.

Multiple CVEs Disclosed on September 8, 2026, Affecting Microsoft Products On September 8, 2026, multiple CVEs were disclosed affecting various Microsoft products, including SharePoint and Office. Key vulnerabilities include improper access controls, buffer overflows, and command injections, which could allow unauthorized code execution and information disclosure. CVE-2026-85880, noted for active exploitation, was added to CISA's KEV list on the same day. Other vulnerabilities, such as CVE-2026-69428 and CVE-2026-69621, also pose significant risks due to their potential for exploitation. Organizations using affected versions of Microsoft products are urged to apply patches immediately to mitigate risks. The vulnerabilities impact a range of systems, including SharePoint Server and Microsoft Office, and could lead to severe consequences if exploited. 927 sources 74

Extracted Entities

CVE-2026-85880 Windows Advanced Local Procedure Call (ALPC) Elevation of Privilege Vulnerability

The full story

Extracted Entities

Attack Types (1)

CVEs (1)

CWE Weaknesses (2)

MITRE ATT&CK (1)

Platforms (1)