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CVE-2026-50307 Microsoft CVE debrief

CVE-2026-50307 is a high-severity vulnerability in Windows TCP/IP that allows an authorized attacker to elevate privileges locally. The vulnerability is caused by a use-after-free issue in the Windows TCP/IP component. This type of vulnerability can be particularly dangerous as it allows an attacker with local access to gain elevated privileges, potentially leading to a complete compromise of the system. System administrators and users of Windows 10, Windows 11, and Windows Server systems should be aware of this vulnerability and take steps to mitigate it. The vulnerability has a CVSS score of 7 and a CVSS severity of HIGH.

Vendor
Microsoft
Product
Windows 10 Version 1809
CVSS
HIGH 7
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 systems should be aware of this vulnerability and take steps to mitigate it. The vulnerability can be particularly dangerous for organizations that rely on Windows-based systems, as it allows an attacker with local access to gain elevated privileges. This could lead to a complete compromise of the system and potentially allow the attacker to move laterally within the network.

Technical summary

The vulnerability is caused by a use-after-free issue in the Windows TCP/IP component. 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. The use-after-free issue occurs when the system attempts to access memory that has already been freed, which can lead to unpredictable behavior and potentially allow an attacker to execute arbitrary code. The official advisory from Microsoft provides guidance on how to mitigate this vulnerability.

Defensive priority

High

Recommended defensive actions

  • Apply the patch provided by Microsoft
  • Ensure that Windows systems are up to date with the latest security patches
  • Monitor systems for suspicious activity
  • Implement additional security controls to prevent exploitation
  • Review compensating controls for exposed systems while remediation is scheduled and verified

Evidence notes

The CVE record was published on 2026-07-14T18:17:28.690Z and was last modified on 2026-07-16T19:41:13.953Z. The NVD entry is currently Analyzed. The vulnerability is a use-after-free issue in the Windows TCP/IP component. The source detail is limited, and defenders should verify the affected scope and severity with the official advisory. The CVE record was last modified on 2026-07-16T19:41:13.953Z, and no additional information has been provided since then.

Sources and references

Verified primary and authoritative sources

  • CVE-2026-50307 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2026-50307

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

  • CVE-2026-50307 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2026-50307

    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.