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CVE-2026-42974 Microsoft CVE debrief

CVE-2026-42974 is a HIGH severity vulnerability in Windows Performance Monitor that allows an unauthorized attacker to execute code over a network. The vulnerability is caused by an integer underflow (wrap or wraparound) and has a CVSS score of 8.1. The vulnerability affects various versions of Windows 11 and Windows Server.

Vendor
Microsoft
Product
Windows 11 version 23H2
CVSS
HIGH 8.1
CISA KEV
Not listed in stored evidence
Original CVE published
2026-06-09
Original CVE updated
2026-07-09
Advisory published
2026-06-09
Advisory updated
2026-07-09

Who should care

Administrators and users of Windows 11 and Windows Server systems should be aware of this vulnerability and take necessary precautions to mitigate it.

Technical summary

The vulnerability is caused by an integer underflow (wrap or wraparound) in Windows Performance Monitor. This allows an unauthorized attacker to execute code over a network. The vulnerability has been assigned a CVSS score of 8.1 and a severity of HIGH.

Defensive priority

HIGH

Recommended defensive actions

  • Apply patches or updates from the vendor as soon as possible.
  • Use secure communication protocols and authentication mechanisms to prevent unauthorized access.
  • Monitor system logs and network traffic for suspicious activity.

Evidence notes

The vulnerability is documented in the CVE record [cve-org] and the NVD detail page [nvd]. The vendor has also provided a mitigation or vendor reference [ref-4].

Sources and references

Verified primary and authoritative sources

  • CVE-2026-42974 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2026-42974

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

  • CVE-2026-42974 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2026-42974

    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.