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CVE-2026-42910 Microsoft CVE debrief

CVE-2026-42910 is a HIGH severity vulnerability in Windows Hotpatch Monitoring Service that allows an authorized attacker to elevate privileges locally. The vulnerability has a CVSS score of 7.8 and was published on [cvePublishedAt](https://www.cve.org/CVERecord?id=CVE-2026-42910) 2026-06-09. The vulnerability affects multiple versions of Windows 11 and Windows Server 2025.

Vendor
Microsoft
Product
Windows Hotpatch Monitoring Service
CVSS
HIGH 7.8
CISA KEV
Not listed in stored evidence
Original CVE published
2026-06-09
Original CVE updated
2026-06-11
Advisory published
2026-06-09
Advisory updated
2026-06-11

Who should care

Administrators and users of affected Windows systems should apply patches to mitigate this vulnerability.

Technical summary

The vulnerability is an out-of-bounds write in Windows Hotpatch Monitoring Service, which 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.

Defensive priority

HIGH

Recommended defensive actions

  • Apply patches from Microsoft as soon as possible.
  • Review and update vulnerability management processes to ensure timely patching of affected systems.

Evidence notes

The vulnerability is based on information from the National Vulnerability Database (NVD) and Microsoft's security advisories.

Sources and references

Verified primary and authoritative sources

  • CVE-2026-42910 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2026-42910

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

  • CVE-2026-42910 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2026-42910

    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.