PatchSiren

PatchSiren cyber security CVE debrief

CVE-2026-20857 Microsoft CVE debrief

AI-assisted PatchSiren debrief based on the supplied source corpus. The CVE record was published on 2026-01-13T18:16:14.480Z and has not been modified since then. The vulnerability CVE-2026-20857 is an untrusted pointer dereference in the Windows Cloud Files Mini Filter Driver. This issue allows an authorized attacker to elevate privileges locally. The Common Vulnerability Scoring System (CVSS) score is 7.8, indicating a HIGH severity. The affected products include various versions of Windows 10, Windows 11, and Windows Server. System administrators and security teams responsible for Windows-based systems, especially those using Windows 10, Windows 11, and Windows Server, should be aware of this vulnerability and take necessary actions to mitigate the risk. This vulnerability allows an authorized attacker to elevate privileges locally, which is a high-risk impact. Affected systems should be prioritized for patching. The CVE-2026-20857 record indicates an untrusted pointer dereference in the Windows Cloud Files Mini Filter Driver, which could allow an authorized attacker to elevate privileges locally. The CVSS score is 7.8 with a HIGH severity. Affected versions of Windows 10, Windows 11, and Windows Server are listed in the CPE criteria.

Vendor
Microsoft
Product
Windows 10 Version 1809
CVSS
HIGH 7.8
CISA KEV
Not listed in stored evidence
Original CVE published
2026-01-13
Original CVE updated
2026-07-30
Advisory published
2026-01-13
Advisory updated
2026-07-30

Who should care

System administrators and security teams responsible for Windows-based systems, especially those using Windows 10, Windows 11, and Windows Server, should be aware of this vulnerability and take necessary actions to mitigate the risk.

Technical summary

The vulnerability CVE-2026-20857 is an untrusted pointer dereference in the Windows Cloud Files Mini Filter Driver. This issue allows an authorized attacker to elevate privileges locally. The Common Vulnerability Scoring System (CVSS) score is 7.8, indicating a HIGH severity. The affected products include various versions of Windows 10, Windows 11, and Windows Server.

Defensive priority

This vulnerability allows an authorized attacker to elevate privileges locally, which is a high-risk impact. Affected systems should be prioritized for patching.

Recommended defensive actions

  • Apply patches or updates provided by Microsoft to address the vulnerability in the Windows Cloud Files Mini Filter Driver.
  • Ensure that all affected systems are identified and prioritized for patching based on their exposure and criticality.
  • Monitor system logs for indicators of compromise related to this vulnerability.

Evidence notes

The CVE-2026-20857 record indicates an untrusted pointer dereference in the Windows Cloud Files Mini Filter Driver, which could allow an authorized attacker to elevate privileges locally. The CVSS score is 7.8 with a HIGH severity. Affected versions of Windows 10, Windows 11, and Windows Server are listed in the CPE criteria.

Sources and references

Verified primary and authoritative sources

  • CVE-2026-20857 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2026-20857

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

  • CVE-2026-20857 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2026-20857

    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.