CVE-2026-85880ImportantExploitedCISA KEV · due 22 SepRevised 16 Sep
Windows Advanced Local Procedure Call (ALPC) Elevation of Privilege Vulnerability
Listed in the CISA Known Exploited Vulnerabilities catalog
Added 8 Sep 2026 · federal remediation due 22 Sep 2026.
Microsoft Windows Advanced Local Procedure Call contains a heap-based buffer overflow vulnerability that allows an attacker to elevate privileges locally.
Assessment
Heap-based buffer overflow in Windows ALPC allows an authorized attacker to elevate privileges locally.
- Severity
- Important
- CVSS base score
- 7.8CVSS:3.1/
AV:L/ AC:L/ PR:L/ UI:N/ S:U/ C:H/ I:H/ A:H/ E:F/ RL:O/ RC:C - Impact
- Elevation of Privilege
- EPSS, next 30 days
- 3.6%Higher than 89.1% of scored CVEs · FIRST model run 26 Sep 2026 · about EPSS
- Exploitability
- Exploitation detected
- Publicly disclosed
- No
- Customer action
- Required: apply the update
- Component
- Windows ALPC
- Weakness
- CWE-122: Heap-based Buffer Overflow
- Issued by
- Microsoft
- Published
- 8 Sep 2026 · September 2026
- Last revised
- 16 Sep 2026CVSS vector modified to correct the temporal Exploit Code Maturity setting. This is an informational change only.
Updates that fix it
6 KBs| KB | Type | Restart | Applies to | Other CVEs |
|---|---|---|---|---|
| KB5122876 | Security Update | Required | Windows 10 Version 1809 for 32-bit Systems, Windows 10 Version 1809 for x64-based Systems, Windows Server 2019 and 1 more | All CVEs in KB5122876 |
| KB5122878 | Security Update | Required | Windows 10 Version 21H2 for 32-bit Systems, Windows 10 Version 21H2 for ARM64-based Systems, Windows 10 Version 21H2 for x64-based Systems and 3 more | All CVEs in KB5122878 |
| KB5122882 | Security Update | Required | Windows Server 2022, Windows Server 2022 (Server Core installation) | All CVEs in KB5122882 |
| KB5123065 | Monthly Rollup | Required | Windows Server 2012, Windows Server 2012 (Server Core installation) | All CVEs in KB5123065 |
| KB5123066 | Monthly Rollup | Required | Windows Server 2012 R2, Windows Server 2012 R2 (Server Core installation) | All CVEs in KB5123066 |
| KB5123099 | Security Update | Required | Windows 10 Version 1607 for 32-bit Systems, Windows 10 Version 1607 for x64-based Systems, Windows Server 2016 and 1 more | All CVEs in KB5123099 |
Affected products
ESU, Windows20 affected products
- Windows 10 Version 1607 for 32-bit Systems
- Windows 10 Version 1607 for x64-based Systems
- Windows 10 Version 1809 for 32-bit Systems
- Windows 10 Version 1809 for x64-based Systems
- Windows 10 Version 21H2 for 32-bit Systems
- Windows 10 Version 21H2 for ARM64-based Systems
- Windows 10 Version 21H2 for x64-based Systems
- Windows 10 Version 22H2 for 32-bit Systems
- Windows 10 Version 22H2 for ARM64-based Systems
- Windows 10 Version 22H2 for x64-based Systems
- Windows Server 2012
- Windows Server 2012 (Server Core installation)
- Windows Server 2012 R2
- Windows Server 2012 R2 (Server Core installation)
- Windows Server 2016
- Windows Server 2016 (Server Core installation)
- Windows Server 2019
- Windows Server 2019 (Server Core installation)
- Windows Server 2022
- Windows Server 2022 (Server Core installation)