Authenticated remote code execution via ReFS heap overflow
Published Dec 9, 2025 · Updated Apr 16, 2026
A heap-based buffer overflow in Microsoft Windows ReFS allows remote authenticated users to execute code over a network. Microsoft has not disclosed the ReFS code path or malformed filesystem-data operation that overruns the heap buffer. Exploitation requires prior authorization and network reachability, and successful exploitation executes attacker-controlled code on the affected Windows host.
Summary
What happened
A heap-based buffer overflow in Microsoft Windows ReFS allows remote authenticated users to execute code over a network. Microsoft has not disclosed the ReFS code path or malformed filesystem-data operation that overruns the heap buffer. Exploitation requires prior authorization and network reachability, and successful exploitation executes attacker-controlled code on the affected Windows host.
The record
- CVE
- CVE-2025-62456
- Published
- Dec 9, 2025
- Updated
- Apr 16, 2026
- Vendor
- Microsoft
- Product
- Windows Server 2025 (Server Core installation)
- Classifications
- CWE-122, T1210
- Attack vector
- network
- Privileges
- authenticated
Timeline
How it unfolded
- Dec 9, 2025CVE publishedPublication date reported by the CVE source.
- Apr 16, 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 <10.0.26100.7462
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.
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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