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PatchSiren cyber security CVE debrief

CVE-2026-62798 Microsoft CVE debrief

An information disclosure vulnerability exists in the Windows Win32K due to an untrusted pointer dereference. This allows an authorized attacker to disclose information locally. The vulnerability affects multiple versions of Windows 11 and Windows Server 2025. A detailed review of the vulnerability indicates that it is a medium-priority issue for defenders, who should assess exposure and apply patches provided by Microsoft. The vulnerability has been publicly disclosed, and defenders should monitor systems for potential information disclosure and verify that affected versions of Windows 11 and Windows Server 2025 are patched. The CVE record and source item provide details on the .

Vendor
Microsoft
Product
Windows 11 version 23H2
CVSS
MEDIUM 5.5
CISA KEV
Not listed in stored evidence
Original CVE published
2026-08-11
Original CVE updated
2026-10-08
Advisory published
2026-08-11
Advisory updated
2026-10-08

Who should care

Defenders responsible for Windows systems, particularly those running affected versions of Windows 11 or Windows Server 2025, should assess exposure and apply patches provided by Microsoft.

Why it matters

The vulnerability allows an authorized attacker to disclose information locally, and defenders should assess exposure and apply patches provided by Microsoft.

  • Assess exposure and apply patches to prevent potential information disclosure
  • Monitor systems for potential information disclosure
  • Verify affected versions of Windows 11 and Windows Server 2025 are patched

Technical summary

The vulnerability exists in the Windows Win32K due to an untrusted pointer dereference. This allows an authorized attacker to disclose information locally. The vulnerability affects multiple versions of Windows 11 and Windows Server 2025, including Windows 11 version 23H2, Windows 11 Version 24H2, Windows 11 Version 25H2, Windows 11 version 26H1, Windows Server 2025, and Windows Server 2025 (Server Core installation).

Defensive priority

Medium priority for defenders to assess exposure and apply patches

Recommended defensive actions

  • Assess exposure by checking if systems are running affected versions of Windows 11 or Windows Server 2025
  • Apply patches provided by Microsoft to address the vulnerability
  • Monitor systems for potential information disclosure

Evidence notes

The CVE record and source item provide details on the vulnerability, but limited information is available on exploitation or impact. The vendor, Microsoft, has provided an advisory and patch for the vulnerability.

Sources and references

Verified primary and authoritative sources

  • CVE-2026-62798 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2026-62798

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

  • CVE-2026-62798 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2026-62798

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

Supplemental references

  • Win32k Information Disclosure Vulnerability

    Unverified legacy reference

    URL: https://raw.githubusercontent.com/CVEProject/cvelistV5/main/cves/2026/62xxx/CVE-2026-62798.json

    cve_program_cvelist_v5

  • Source reference

    Unverified legacy reference

    URL: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-62798

    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.