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CVE-2026-50305 Microsoft CVE debrief

CVE-2026-50305 is a high-severity vulnerability in Microsoft Brokering File System, which is caused by a use-after-free issue. This issue allows an authorized attacker to elevate privileges locally. The CVSS score for this vulnerability is 7.8, indicating a high level of severity. Affected products include Windows 11 24H2, 25H2, 26H1, and Windows Server 2025. Administrators and users of these systems should be aware of this vulnerability and take necessary precautions to mitigate its effects. The vulnerability has a significant impact on the security of affected systems, and its exploitation could lead to unauthorized privilege escalation.

Vendor
Microsoft
Product
Windows 11 Version 24H2
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

Administrators and users of Microsoft Windows 11 and Windows Server 2025 systems should be aware of this vulnerability and take necessary precautions to mitigate its effects. This includes reviewing system configurations, applying patches or updates, and implementing compensating controls. Additionally, security teams and vulnerability management teams should prioritize this vulnerability due to its high severity and potential impact on system security.

Technical summary

The vulnerability is caused by a use-after-free issue in the Microsoft Brokering File System. This issue allows an authorized attacker to elevate privileges 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, indicating a high level of severity. Affected products include Windows 11 24H2, 25H2, 26H1, and Windows Server 2025.

Defensive priority

High

Recommended defensive actions

  • Apply patches or updates provided by Microsoft to vulnerable systems
  • Implement compensating controls, such as monitoring and exception tracking
  • Conduct inventory checks to identify vulnerable systems
  • Consider implementing additional security measures, such as access controls and intrusion detection systems
  • Review and verify system configurations to ensure they align with security best practices

Evidence notes

The CVE record was published on 2026-07-14T18:17:28.377Z and was last modified on 2026-07-16T19:41:59.217Z. The NVD entry is currently Analyzed. The vulnerability is caused by a use-after-free issue in the Microsoft Brokering File System. The source detail is limited, and defenders should verify the affected scope, severity, and vendor guidance. The CVE record and NVD entry provide evidence of the vulnerability's existence and its potential impact.

Sources and references

Verified primary and authoritative sources

  • CVE-2026-50305 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2026-50305

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

  • CVE-2026-50305 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2026-50305

    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.