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CVE-2026-49173 Microsoft CVE debrief

CVE-2026-49173 is a high-severity vulnerability in Windows Kernel, allowing an authorized attacker to elevate privileges locally. The vulnerability has a CVSS score of 7.8 and is classified as HIGH. The vulnerability is a use-after-free issue in the Windows Kernel. System administrators and security teams responsible for Windows Kernel systems should be aware of this vulnerability and take necessary actions to mitigate it. The CVE record was published on 2026-07-14T17:16:52.390Z and was last modified on 2026-07-20T13:34:07.037Z.

Vendor
Microsoft
Product
Windows 11 version 26H1
CVSS
HIGH 7.8
CISA KEV
Not listed in stored evidence
Original CVE published
2026-07-14
Original CVE updated
2026-07-22
Advisory published
2026-07-14
Advisory updated
2026-07-22

Who should care

System administrators and security teams responsible for Windows Kernel systems should be aware of this vulnerability and take necessary actions to mitigate it. Operators of Windows Kernel systems, platform administrators, and security teams should review system configurations and monitor system logs for suspicious activity.

Technical summary

The vulnerability is a use-after-free issue in the Windows Kernel, which allows an authorized attacker to elevate privileges locally. The CVSS vector is CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H. The vulnerability has a CVSS score of 7.8 and is classified as HIGH. The Windows Kernel vulnerability allows an authorized attacker to elevate privileges locally.

Defensive priority

High priority should be given to patching this vulnerability, as it allows for local privilege escalation.

Recommended defensive actions

  • Apply the patch provided by Microsoft
  • Review system configurations and ensure that only authorized users have access to sensitive areas
  • Monitor system logs for suspicious activity
  • Consider implementing additional security controls, such as access controls and intrusion detection systems
  • Review compensating controls for exposed systems while remediation is scheduled and verified

Evidence notes

The CVE record was published on 2026-07-14T17:16:52.390Z and was last modified on 2026-07-20T13:34:07.037Z. The NVD entry is currently Analyzed. The vulnerability has a CVSS score of 7.8 and is classified as HIGH. The Windows Kernel vulnerability allows an authorized attacker to elevate privileges locally. Evidence of exploitation is not currently available, but defenders should verify system configurations and monitor system logs for suspicious activity.

Sources and references

Verified primary and authoritative sources

  • CVE-2026-49173 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2026-49173

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

  • CVE-2026-49173 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2026-49173

    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.