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CVE-2026-42991 Microsoft CVE debrief

CVE-2026-42991 is a HIGH-severity vulnerability (CVSS Score: 7.8) in Windows Push Notifications, allowing an authorized attacker to elevate privileges locally due to a race condition. The vulnerability was published on 2026-06-09 and last modified on 2026-06-11.

Vendor
Microsoft
Product
Windows 10 Version 1809
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 Microsoft Windows versions should prioritize patching this vulnerability to prevent local privilege escalation attacks.

Technical summary

The vulnerability (CVE-2026-42991) is caused by a race condition in Windows Push Notifications, which allows an authorized attacker to elevate privileges locally. It has been assigned a CVSS Score of 7.8 and CVSS Severity of HIGH.

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 critical vulnerabilities.
  • Monitor systems for suspicious activity that could indicate exploitation attempts.

Evidence notes

The CVE-2026-42991 record was obtained from the official CVE.org and NVD databases.

Official resources

CVE-2026-42991 was published on 2026-06-09 and last modified on 2026-06-11.