Local privilege escalation via ALPC heap overflow
Published Sep 8, 2026 · Updated Sep 9, 2026
Heap-based buffer overflow in Microsoft Windows ALPC allows local users with low privileges to elevate privileges on affected systems. Microsoft identifies heap overflow and use of an uninitialized resource, but has not disclosed the ALPC routine, input, or exact incorrect memory operation. Exploitation requires local low-privilege access and no user interaction; CISA reports active exploitation, but the resulting privilege level is undisclosed.
Summary
What happened
Heap-based buffer overflow in Microsoft Windows ALPC allows local users with low privileges to elevate privileges on affected systems. Microsoft identifies heap overflow and use of an uninitialized resource, but has not disclosed the ALPC routine, input, or exact incorrect memory operation. Exploitation requires local low-privilege access and no user interaction; CISA reports active exploitation, but the resulting privilege level is undisclosed.
The record
- CVE
- CVE-2026-85880
- Published
- Sep 8, 2026
- Updated
- Sep 9, 2026
- Vendor
- Microsoft
- Product
- Windows Server 2019
- Classifications
- CWE-908, CWE-122, T1068
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Sep 8, 2026CVE publishedPublication date reported by the CVE source.
- Sep 9, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=10.0.17763.0 <10.0.17763.9245
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
No public exploit references are available in this record.
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Reported exploitation
- CISA Known Exploited Vulnerabilities Catalog listingknown exploited catalog
Technologies
Your stack
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Your stack
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