PatchSiren

PatchSiren cyber security CVE debrief

CVE-2026-54109 Microsoft CVE debrief

CVE-2026-54109 is an integer overflow or wraparound vulnerability in Windows Resilient File System (ReFS). An authorized attacker can exploit this vulnerability to execute code locally. The vulnerability has a CVSS score of 7.8 and is classified as HIGH severity. The vulnerability exists in Windows Resilient File System (ReFS) and can be exploited by an authorized attacker to execute code locally. The vulnerability is caused by an integer overflow or wraparound. Affected products include Windows 10, Windows 11, and Windows Server.

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 allows an authorized attacker to execute code locally. The vulnerability has a CVSS score of 7.8 and is classified as HIGH severity.

Technical summary

The vulnerability exists in the Windows Resilient File System (ReFS) and can be exploited by an authorized attacker to execute code locally. The vulnerability is caused by an integer overflow or wraparound. Affected products include Windows 10, Windows 11, and Windows Server. The CVSS score is 7.8 and is classified as HIGH severity.

Defensive priority

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

Recommended defensive actions

  • Apply patches provided by Microsoft
  • Ensure Windows 10, Windows 11, and Windows Server systems are up-to-date
  • Monitor systems for suspicious activity
  • Implement compensating controls such as access controls and intrusion detection systems
  • Review relevant monitoring, detection, and logs for exposed assets that need extra review

Evidence notes

The CVE record was published on 2026-07-14T17:17:03.853Z and was last modified on 2026-07-22T16:18:13.213Z. The NVD entry is currently Analyzed. The vulnerability exists in Windows Resilient File System (ReFS) and can be exploited by an authorized attacker to execute code locally. The vulnerability is caused by an integer overflow or wraparound. Affected products include Windows 10, Windows 11, and Windows Server. The CVSS score is 7.8 and is classified as HIGH severity.

Sources and references

Verified primary and authoritative sources

  • CVE-2026-54109 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2026-54109

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

  • CVE-2026-54109 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2026-54109

    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.