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CVE-2026-85854 Microsoft CVE debrief

The Windows DWM Core Library Elevation of Privilege Vulnerability is a use-after-free issue allowing authorized attackers to elevate privileges locally. Defenders responsible for Windows systems, particularly those using Windows 10 Version 1809, Windows 10 Version 21H2, Windows 10 Version 22H2, Windows 11 version 23H2, Windows 11 Version 23H2, Windows 11 Version 24H2, Windows 11 Version 25H2, Windows 11 version 26H1, Windows 11 Version 26H2, Windows Server 2019, Windows Server 2019 (Server Core installation), Windows Server 2022, Windows Server 2025, and Windows Server 2025 (Server Core installation), should assess exposure and apply patches. The CVE record was published on 2026-10

Vendor
Microsoft
Product
Windows 10 Version 1809
CVSS
HIGH 7
CISA KEV
Not listed in stored evidence
Original CVE published
2026-10-13
Original CVE updated
2026-10-13
Advisory published
2026-10-13
Advisory updated
2026-10-13

Who should care

Defenders responsible for Windows systems, particularly those using Windows 10 Version 1809, Windows 10 Version 21H2, Windows 10 Version 22H2, Windows 11 version 23H2, Windows 11 Version 23H2, Windows 11 Version 24H2, Windows 11 Version 25H2, Windows 11 version 26H1, Windows 11 Version 26H2, Windows Server 2019, Windows Server 2019 (Server Core installation), Windows Server 2022, Windows Server 2025, and Windows Server 2025 (Server Core installation), should assess exposure and apply patches.

Why it matters

The Windows DWM Core Library Elevation of Privilege Vulnerability allows an authorized attacker to elevate privileges locally, posing a significant risk to Windows systems. Defenders should prioritize verifying exposure and applying patches.

  • Verify exposure of Windows DWM Core Library to elevation of privilege attacks
  • Apply patches from Microsoft for affected Windows versions
  • Monitor for unauthorized privilege escalation attempts
  • Review and update incident response plans for potential elevation of privilege attacks

Technical summary

The Windows DWM Core Library Elevation of Privilege Vulnerability allows an authorized attacker to elevate privileges locally due to a use-after-free issue in the Windows DWM Core Library. This vulnerability affects Windows 10 Version 1809, Windows 10 Version 21H2, Windows 10 Version 22H2, Windows 11 version 23H2, Windows 11 Version 23H2, Windows 11 Version 24H2, Windows 11 Version 25H2, Windows 11 version 26H1, Windows 11 Version 26H2, Windows Server 2019, Windows Server 2019 (Server Core installation), Windows Server 2022, Windows Server 2025, and Windows Server

Defensive priority

Defenders should prioritize verifying exposure and applying patches for Windows DWM Core Library Elevation of Privilege Vulnerability.

Recommended defensive actions

  • Verify exposure of Windows DWM Core Library to elevation of privilege attacks
  • Apply patches from Microsoft for affected Windows versions
  • Monitor for unauthorized privilege escalation attempts
  • Review and update incident response plans for potential elevation of privilege attacks

Evidence notes

The CVE Program record and NVD vulnerability detail provide information on the vulnerability. Microsoft's official advisory is referenced. The vulnerability has a CVSS score of 7.0 and is classified as HIGH severity. The CVE record was published on 2026-10-13T19:00:09.323Z and has not been modified since then. The NVD entry is currently 7.0. The source item providing details on the vulnerability is from cve_program_cvelist_v5.

Sources and references

Verified primary and authoritative sources

  • CVE-2026-85854 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2026-85854

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

  • CVE-2026-85854 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2026-85854

    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.