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CVE-2026-33841 Microsoft CVE debrief

CVE-2026-33841 is a high-severity vulnerability in the Windows Kernel that allows an authorized attacker to elevate privileges locally. The vulnerability has a CVSS score of 7.8 and is classified as HIGH. It was published on May 12, 2026, and last modified on June 17, 2026. The vulnerability affects various versions of Windows 10, Windows 11, and Windows Server. Microsoft has provided a vendor advisory for this vulnerability.

Vendor
Microsoft
Product
Windows 10 Version 21H2
CVSS
HIGH 7.8
CISA KEV
Not listed in stored evidence
Original CVE published
2026-05-12
Original CVE updated
2026-06-17
Advisory published
2026-05-12
Advisory updated
2026-06-17

Who should care

System administrators and security teams responsible for Windows-based systems should be aware of this vulnerability and take necessary actions to mitigate it. This vulnerability can be used by an authorized attacker to elevate privileges locally, which can lead to further exploitation.

Technical summary

The vulnerability is a heap-based buffer overflow in the Windows Kernel. It allows an authorized attacker to elevate privileges locally. The vulnerability has been assigned a CVSS vector of CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H. The CWE associated with this vulnerability is CWE-122.

Defensive priority

High

Recommended defensive actions

  • Apply the patch provided by Microsoft to vulnerable systems.
  • Ensure that all Windows-based systems are up-to-date with the latest security patches.
  • Implement a defense-in-depth strategy to limit the attack surface.
  • Monitor system logs for suspicious activity.
  • Restrict access to sensitive areas of the system.
  • Use a reputable security software to detect and prevent exploitation.
  • Verify that all systems are running with the principle of least privilege.

Evidence notes

The information provided is based on the CVE record and the NVD detail page. The CVE record was published on May 12, 2026, and last modified on June 17, 2026. The NVD detail page provides additional information on the vulnerability, including its CVSS score and CWE association.

Sources and references

Verified primary and authoritative sources

  • CVE-2026-33841 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2026-33841

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

  • CVE-2026-33841 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2026-33841

    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.