Local privilege escalation via ReFS heap overflow
Published Sep 8, 2026 · Updated Sep 10, 2026
Heap-based buffer overflow in Microsoft Windows ReFS allows local users with low privileges to elevate privileges on affected systems. ReFS writes beyond an allocated heap buffer while processing undisclosed local input; Microsoft has not published the function or input format. Successful exploitation requires local authenticated access and grants elevated privileges, with no reported remote attack path.
Summary
What happened
Heap-based buffer overflow in Microsoft Windows ReFS allows local users with low privileges to elevate privileges on affected systems. ReFS writes beyond an allocated heap buffer while processing undisclosed local input; Microsoft has not published the function or input format. Successful exploitation requires local authenticated access and grants elevated privileges, with no reported remote attack path.
The record
- CVE
- CVE-2026-83952
- Published
- Sep 8, 2026
- Updated
- Sep 10, 2026
- Vendor
- Microsoft
- Product
- Windows Server 2025 (Server Core installation)
- Classifications
- CWE-122, T1068
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Sep 8, 2026CVE publishedPublication date reported by the CVE source.
- Sep 10, 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=10.0.26100.0 <10.0.26100.33438
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.
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Technologies
Your stack
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Your stack
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