Actively exploited · Published Sep 8, 2026 · Assigned by microsoft

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

High 7.8 Exploited

In plain English

A high-severity heap buffer overflow in Windows 10 Version 1607 from Microsoft. Attackers are actively exploiting it in the wild (listed by CISA on September 8, 2026). The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 33% of all known vulnerabilities). Apply mitigations in accordance with vendor instructions, ensuring compliance with CISA’s BOD 26-04 Prioritizing Security Updates Based on Risk (see URL in Notes) guidance and CISA’s “Forensics Triage Requirements” (see URL in Notes). Follow applicable BOD 26-04 guidance for cloud services or discontinue use of the product if mitigations are unavailable. Stakeholders are responsible for evaluating each asset's internet exposure and ensuring adherence to BOD 26-04 patching guidelines.

Severity (CVSS 3.1)7.8High
Exploit odds (30 days)0.4%top 67.0% of all CVEs
Exploited in the wildYesCISA KEV since Sep 8, 2026
Attack toolingNoneno public tooling known

CISA guidance

Apply mitigations in accordance with vendor instructions, ensuring compliance with CISA’s BOD 26-04 Prioritizing Security Updates Based on Risk (see URL in Notes) guidance and CISA’s “Forensics Triage Requirements” (see URL in Notes). Follow applicable BOD 26-04 guidance for cloud services or discontinue use of the product if mitigations are unavailable. Stakeholders are responsible for evaluating each asset's internet exposure and ensuring adherence to BOD 26-04 patching guidelines.

Federal agencies must remediate by Sep 22, 2026.

Official description

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

Affected products (as reported)

VendorProductVersions
Microsoft Windows 10 Version 1607 10.0.14393.0 – before 10.0.14393.9512
Microsoft Windows 10 Version 1809 10.0.17763.0 – before 10.0.17763.9245
Microsoft Windows 10 Version 21H2 10.0.19044.0 – before 10.0.19044.7725
Microsoft Windows 10 Version 22H2 10.0.19045.0 – before 10.0.19045.7725
Microsoft Windows Server 2012 6.2.9200.0 – before 6.2.9200.26349
Microsoft Windows Server 2012 (Server Core installation) 6.2.9200.0 – before 6.2.9200.26349
Microsoft Windows Server 2012 R2 6.3.9600.0 – before 6.3.9600.23398
Microsoft Windows Server 2012 R2 (Server Core installation) 6.3.9600.0 – before 6.3.9600.23398
Microsoft Windows Server 2016 10.0.14393.0 – before 10.0.14393.9512
Microsoft Windows Server 2016 (Server Core installation) 10.0.14393.0 – before 10.0.14393.9512
Microsoft Windows Server 2019 10.0.17763.0 – before 10.0.17763.9245
Microsoft Windows Server 2019 (Server Core installation) 10.0.17763.0 – before 10.0.17763.9245
Microsoft Windows Server 2022 10.0.20348.0 – before 10.0.20348.5622

Weakness: CWE-122, CWE-908 · Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:F/RL:O/RC:C

References