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CVE-2026-56648 Microsoft CVE debrief

A time-of-check time-of-use (TOCTOU) race condition vulnerability exists in the Windows Network File System. This vulnerability allows an authorized attacker to elevate privileges over a network. The vulnerability is caused by a TOCTOU race condition, which occurs when an attacker can manipulate the system between the time of a security check and the time of use. System administrators and users of Windows operating systems should be aware of this vulnerability, as it could allow attackers to gain elevated privileges.

Vendor
Microsoft
Product
Windows 10 Version 1607
CVSS
HIGH 7.5
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 operating systems should be aware of this vulnerability, as it could allow attackers to gain elevated privileges. Affected operators, platform administrators, vulnerability management teams, and security teams should review and act on this vulnerability.

Technical summary

The vulnerability is caused by a TOCTOU race condition in the Windows Network File System. This type of vulnerability occurs when an attacker can manipulate the system between the time of a security check and the time of use, allowing them to bypass security restrictions. In this case, an authorized attacker could exploit the vulnerability to elevate their privileges over a network.

Defensive priority

High

Recommended defensive actions

  • Apply patches from Microsoft as soon as available
  • Implement compensating controls such as monitoring and access restrictions
  • Conduct regular vulnerability assessments and inventory checks
  • 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 2026-07-14T18:18:31.127Z and was last modified on 2026-07-17T13:43:56.007Z. The NVD entry is currently Analyzed. This vulnerability affects Windows Network File System, allowing authorized attackers to elevate privileges over a network. Evidence is based on CVE.org and NVD details. Defenders should verify system configurations and patch levels.

Sources and references

Verified primary and authoritative sources

  • CVE-2026-56648 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2026-56648

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

  • CVE-2026-56648 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2026-56648

    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.