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CVE-2026-50407 Microsoft CVE debrief

A heap-based buffer overflow vulnerability exists in the Windows Resilient File System (ReFS). An authorized attacker could exploit this vulnerability to elevate privileges locally on Windows 10, Windows 11, and Windows Server systems. The vulnerability has a CVSS score of 7.8 and is classified as HIGH severity. The vulnerability is caused by a heap-based buffer overflow in the Windows Resilient File System (ReFS).

Vendor
Microsoft
Product
Windows 10 Version 1607
CVSS
HIGH 7.8
CISA KEV
Not listed in stored evidence
Original CVE published
2026-07-14
Original CVE updated
2026-07-20
Advisory published
2026-07-14
Advisory updated
2026-07-20

Who should care

System administrators and users of Windows 10, Windows 11, and Windows Server systems should be aware of this vulnerability and apply patches as available. The vulnerability has a CVSS score of 7.8 and is classified as HIGH severity.

Technical summary

The vulnerability is a heap-based buffer overflow in the Windows Resilient File System (ReFS). This could allow an authorized attacker to elevate privileges locally on Windows 10, Windows 11, and Windows Server systems. The vulnerability has a CVSS score of 7.8 and is classified as HIGH severity. The vulnerability affects Windows 10, Windows 11, and Windows Server systems.

Defensive priority

High

Recommended defensive actions

  • Apply patches as available from Microsoft
  • Ensure systems are up to date with the latest security updates
  • Monitor system logs for suspicious activity
  • Implement compensating controls such as access controls and intrusion detection systems
  • Review relevant monitoring, detection, and logs for exposed assets that need extra review

Evidence notes

The CVE record was published on 2026-07-14T18:17:43.333Z and was last modified on 2026-07-20T14:20:44.383Z. The NVD entry is currently Analyzed. This vulnerability affects Windows 10, Windows 11, and Windows Server systems. The vulnerability has a CVSS score of 7.8 and is classified as HIGH severity. The NVD entry provides additional details on the vulnerability. The CVE record was last modified on 2026-07-20T14:20:44.383Z.

Sources and references

Verified primary and authoritative sources

  • CVE-2026-50407 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2026-50407

    CVE Program - Official CVE Program record with source-provided CVE metadata.

  • CVE-2026-50407 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2026-50407

    NIST National Vulnerability Database - Official NIST NVD detail page and source-specific vulnerability assessment.

Supplemental references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.