PatchSiren

PatchSiren cyber security CVE debrief

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.

Sources and references

Verified primary and authoritative sources

  • CVE-2026-42991 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2026-42991

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

  • CVE-2026-42991 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2026-42991

    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.