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CVE-2026-50406 Microsoft CVE debrief

CVE-2026-50406 is a high-severity vulnerability in Windows Backup Engine, caused by a use-after-free issue that allows an authorized attacker to elevate privileges locally. The vulnerability has a CVSS score of 7 and a CVSS severity of HIGH. Microsoft has patched this vulnerability, and system administrators should apply the patch to prevent potential privilege escalation attacks. The vulnerability affects Windows 10, Windows 11, and Windows Server.

Vendor
Microsoft
Product
Windows 10 Version 21H2
CVSS
HIGH 7
CISA KEV
Not listed in stored evidence
Original CVE published
2026-07-14
Original CVE updated
2026-07-23
Advisory published
2026-07-14
Advisory updated
2026-07-23

Who should care

System administrators and users of Windows 10, Windows 11, and Windows Server should apply the patch to prevent potential privilege escalation attacks. Security teams should review the vulnerability and ensure that affected systems are patched or mitigated.

Technical summary

The vulnerability is caused by a use-after-free issue in Windows Backup Engine. An authorized attacker can exploit this vulnerability to elevate privileges locally. The vulnerability has a CVSS score of 7 and a CVSS severity of HIGH. Microsoft has provided a patch for this vulnerability, which should be applied to prevent potential exploitation.

Defensive priority

High

Recommended defensive actions

  • Apply the patch provided by Microsoft
  • Ensure Windows Backup Engine is up-to-date
  • Monitor system logs for potential exploitation attempts
  • Review compensating controls for exposed systems while remediation is scheduled and verified
  • Check relevant monitoring, detection, and logs for exposed assets that need extra review

Evidence notes

The CVE record was published on 2026-07-14T18:17:43.210Z and was last modified on 2026-07-20T14:21:37.647Z. The NVD entry is currently Analyzed. The vulnerability affects Windows 10, Windows 11, and Windows Server. Microsoft has patched this vulnerability. However, defenders should verify the patch application and monitor system logs for potential exploitation attempts.

Sources and references

Verified primary and authoritative sources

  • CVE-2026-50406 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2026-50406

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

  • CVE-2026-50406 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2026-50406

    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.