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CVE-2026-20863 Microsoft CVE debrief

AI-assisted PatchSiren debrief based on the supplied source corpus. The CVE record was published on 2026-01-13T18:16:15.467Z and has not been modified since then. CVE-2026-20863 is a double free vulnerability in the Windows Win32K - ICOMP component. This vulnerability can be exploited by an authorized attacker to elevate privileges locally. The vulnerability has been assigned a CVSS score of 7 and is considered HIGH severity. Affected products include Windows 11 23H2, 24H2, and 25H2, as well as Windows Server 2022, 2022 23H2, and 2025. Windows system administrators, security teams, and organizations that use these products should be aware of this vulnerability and take necessary actions to mitigate the risk. The CVE record indicates a double free vulnerability in Windows Win32K - ICOMP, which can be exploited locally to elevate privileges. The vulnerability has a CVSS score of 7 and is classified as HIGH severity.

Vendor
Microsoft
Product
Windows 11 version 23H2
CVSS
HIGH 7
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

Windows system administrators, security teams, and organizations that use Windows 11 and Windows Server should be aware of this vulnerability and take necessary actions to mitigate the risk.

Technical summary

CVE-2026-20863 is a double free vulnerability in the Windows Win32K - ICOMP component. This vulnerability can be exploited by an authorized attacker to elevate privileges locally. The vulnerability has been assigned a CVSS score of 7 and is considered HIGH severity. Affected products include Windows 11 23H2, 24H2, and 25H2, as well as Windows Server 2022, 2022 23H2, and 2025.

Defensive priority

This vulnerability allows an authorized attacker to elevate privileges locally, which can have a significant impact on the security of a Windows system.

Recommended defensive actions

  • Review and apply patches from Microsoft for CVE-2026-20863
  • Conduct a thorough inventory of Windows systems to identify potential exposure
  • Implement compensating controls to monitor and restrict local privilege escalation attempts
  • Verify and enforce secure configuration and hardening guidelines for Windows systems

Evidence notes

The CVE-2026-20863 record indicates a double free vulnerability in Windows Win32K - ICOMP, which can be exploited locally to elevate privileges. The vulnerability has a CVSS score of 7 and is classified as HIGH severity. Affected products include various versions of Windows 11 and Windows Server.

Sources and references

Verified primary and authoritative sources

  • CVE-2026-20863 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2026-20863

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

  • CVE-2026-20863 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2026-20863

    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.