Local code execution via ReFS integer overflow
Published Jul 14, 2026 · Updated Jul 14, 2026
Integer overflow in Microsoft Windows ReFS allows local users to execute code by triggering heap-based memory corruption. Microsoft identifies integer wraparound and a resulting heap buffer overflow in ReFS but has not disclosed the affected calculation, structure, or function. Low-privilege local access is required, and successful exploitation runs code on the affected Windows host without user interaction.
Summary
What happened
Integer overflow in Microsoft Windows ReFS allows local users to execute code by triggering heap-based memory corruption. Microsoft identifies integer wraparound and a resulting heap buffer overflow in ReFS but has not disclosed the affected calculation, structure, or function. Low-privilege local access is required, and successful exploitation runs code on the affected Windows host without user interaction.
The record
- CVE
- CVE-2026-54109
- Published
- Jul 14, 2026
- Updated
- Jul 14, 2026
- Vendor
- Microsoft
- Product
- Windows Server 2019
- Classifications
- CWE-122, CWE-190, T1203
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Jul 14, 2026CVE publishedPublication date reported by the CVE source.
- Jul 14, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
Compare your product and version with the public record. A matching version still requires validation against your environment.
Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=10.0.17763.0 <10.0.17763.9020
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.
Technologies
Your stack
See the directory against your own environment.
Your stack
Check the software in your environment
Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.
Book a demo