CVE-2026-50362: Microsoft Windows ReFS heap overflow

CVE-2026-50362 · Severity: high · CVSS 7.8 · Published 2026-07-14

A security vulnerability exists in the Windows Resilient File System (ReFS), a component used to manage and protect large amounts of data on Windows servers and workstations. An attacker who successfully exploits this flaw could gain the ability to run malicious code on the affected system. While the attack requires local access or user interaction, it could lead to a complete compromise of the machine, including data theft or system disruption.

Technologies: Microsoft Windows 11, Microsoft Windows Server, Microsoft Windows 10. Vendors: Microsoft.

Quick answers

Is CVE-2026-50362 exploited in the wild?
No. Junglewise Threat Intelligence has no report of CVE-2026-50362 being exploited in the wild.
How severe is CVE-2026-50362?
High severity, with a CVSS score of 7.8, published 14 July 2026.
Which products and versions are affected?
Microsoft Windows 11 Multiple versions prior to July 2026 updates; Microsoft Windows Server Multiple versions prior to July 2026 updates; Microsoft Windows 10 Multiple versions prior to July 2026 updates.
Is there a fix for CVE-2026-50362?
No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.
How is CVE-2026-50362 attacked?
It is attacked with local access, in an operating system.
Am I affected by CVE-2026-50362?
Check whether you run Microsoft Windows 11, Microsoft Windows Server or Microsoft Windows 10 at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

Technical details

A heap-based buffer overflow vulnerability (CWE-122) exists within the Windows Resilient File System (ReFS) driver. The flaw is triggered when the system processes specially crafted file system metadata, leading to memory corruption. Although the attack vector is classified as local, the CVSS vector indicates that user interaction is required, suggesting an attacker might need to entice a user to mount a malicious ReFS volume or open a crafted file. Successful exploitation allows for arbitrary code execution with the privileges of the ReFS driver, typically resulting in full system compromise. Microsoft has released security updates to address this issue across supported versions of Windows 10, 11, and Windows Server.

Affected products

  • Microsoft Windows 10 Version 1607 / 1809 / 21H2 / 22H2 Multiple versions prior to July 2026 updates
  • Microsoft Windows 11 Version 24H2 / 25H2 / 26H1 Multiple versions prior to July 2026 updates
  • Microsoft Windows Server 2016 / 2019 / 2022 / 2025 Multiple versions prior to July 2026 updates

Timeline

  • 2026-07-14: disclosed: Initial disclosure by Microsoft and NVD
  • 2026-07-14: advisory: Microsoft Security Update Guide published

References

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