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CVE-2026-50309 Microsoft CVE debrief

A high-severity vulnerability, CVE-2026-50309, exists in Windows NTFS, allowing an authorized attacker to execute code locally. This heap-based buffer overflow vulnerability has a CVSS score of 7.8, indicating high severity. The vulnerability can be exploited by an authorized attacker to execute code locally, potentially leading to significant impact. System administrators and users of Windows 10, Windows 11, and Windows Server are advised to take action as this vulnerability can allow an authorized attacker to execute code locally. The CVE record was published on 2026-07-14T18:17:29.013Z and was last modified on 2026-07-16T19:47:33.743Z.

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
2026-07-22
Advisory published
2026-07-14
Advisory updated
2026-07-22

Who should care

System administrators and users of Windows 10, Windows 11, and Windows Server are advised to take action as this vulnerability can allow an authorized attacker to execute code locally. This vulnerability has a CVSS score of 7.8, indicating high severity. Operators, platform administrators, and security teams should prioritize patching and review system logs for suspicious activity.

Technical summary

The vulnerability is a heap-based buffer overflow in Windows NTFS. An authorized attacker can exploit this vulnerability to execute code locally. The CVSS vector for this vulnerability is CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H. The vulnerability has a CVSS score of 7.8, indicating high severity. Affected products include Windows 10, Windows 11, and Windows Server. Defensive measures include applying patches, reviewing and updating Windows NTFS configurations, and monitoring system logs for suspicious activity.

Defensive priority

High priority should be given to patching this vulnerability as it can allow an authorized attacker to execute code locally.

Recommended defensive actions

  • Apply the patch provided by Microsoft
  • Review and update Windows NTFS configurations
  • Monitor system logs for suspicious activity
  • Implement additional security measures to prevent local code execution
  • Review compensating controls for exposed systems while remediation is scheduled and verified

Evidence notes

The CVE record was published on 2026-07-14T18:17:29.013Z and was last modified on 2026-07-16T19:47:33.743Z. The NVD entry is currently Analyzed. The vulnerability is a heap-based buffer overflow in Windows NTFS, allowing an authorized attacker to execute code locally. The CVSS score is 7.8, indicating high severity. System administrators and users of Windows 10, Windows 11, and Windows Server should take action. Evidence limits suggest verifying patch application and reviewing system logs for suspicious activity.

Sources and references

Verified primary and authoritative sources

  • CVE-2026-50309 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2026-50309

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

  • CVE-2026-50309 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2026-50309

    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.