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CVE-2026-69535 Microsoft CVE debrief

A numeric truncation error in Windows Spaceport.sys allows an authorized attacker to elevate privileges locally. This vulnerability affects multiple Windows versions, including 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 Server 2022, and Windows Server 2025, and requires immediate attention from system administrators and security teams. The vulnerability could allow attackers to gain elevated access, potentially leading to further exploitation. System administrators must verify and apply patches to prevent exploitation. Affected systems require

Vendor
Microsoft
Product
Windows 10 Version 21H2
CVSS
HIGH 7.8
CISA KEV
Not listed in stored evidence
Original CVE published
2026-09-08
Original CVE updated
2026-10-08
Advisory published
2026-09-08
Advisory updated
2026-10-08

Who should care

System administrators and security teams responsible for Windows systems, particularly those using affected versions, should assess exposure and apply patches or mitigations as needed.

Why it matters

CVE-2026-69535 is a high-severity elevation of privilege vulnerability in Windows Spaceport.sys, affecting multiple Windows versions. System administrators and security teams must assess exposure and apply patches or mitigations to prevent local privilege escalation.

  • Local privilege escalation could allow attackers to gain elevated access, potentially leading to further exploitation.
  • System administrators must verify and apply patches to prevent exploitation.
  • Affected systems require immediate inventory checks and potential updates.
  • Remediation priority is high due to the potential for local privilege escalation.

Technical summary

The numeric truncation error in Windows Spaceport.sys allows an authorized attacker to elevate privileges locally. Affected versions include 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 Server 2022, and Windows Server 2025.

Defensive priority

High

Recommended defensive actions

  • Assess exposure for 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 Server 2022, and
  • Apply patches from Microsoft for affected Windows versions
  • Verify system configurations and inventory for potential exposure

Evidence notes

The CVE Program and NVD provide official records of this vulnerability. Microsoft has released a patch for this issue. The vulnerability affects multiple Windows versions, including 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 Server 2022, and Windows Server 2025. System administrators and security teams should assess exposure and apply patches or

Sources and references

Verified primary and authoritative sources

  • CVE-2026-69535 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2026-69535

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

  • CVE-2026-69535 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2026-69535

    NIST National Vulnerability Database - Official NIST NVD detail page and source-specific vulnerability assessment.

Supplemental references

  • Windows Spaceport.sys Elevation of Privilege Vulnerability

    Unverified legacy reference

    URL: https://raw.githubusercontent.com/CVEProject/cvelistV5/main/cves/2026/69xxx/CVE-2026-69535.json

    cve_program_cvelist_v5

  • Source reference

    Unverified legacy reference

    URL: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-69535

    Supplemental source - vendor-advisory, patch

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.