CVE-2026-42828: Windows Projected File System Elevation of Privilege Vulnerability

highCVSS 7.8CVE-2026-42828

Buffer over-read in Windows Projected File System Filter Driver allows an authorized attacker to elevate privileges locally.

CSIRTS triage

vendor: Microsoft product: Windows Privilege escalation

What: Buffer over-read in Windows Projected File System Filter Driver allows an authorized attacker to elevate privileges locally.
Who is affected: Users of Windows with the Projected File System feature enabled.
Urgency: Remediation is important but not urgent as there is no active exploitation reported.
Action: Update Windows to the latest version to mitigate the vulnerability.

AI-assisted analysis generated from the source advisory — verify against the original.

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Details

Source: Microsoft Security Response Center (INTL · vendor-psirt · site)
Severity: high — CVSS 7.8
Published: 2026-06-09
Exploitation: Not in CISA KEV at last sync

Original advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-42828

Exploitation outlook

EPSS (FIRST.org) estimates each CVE’s probability of exploitation in the next 30 days — here is the CSIRTS.com read on those numbers.

Low exploitation riskCVE-2026-428280.33% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 25% of all scored CVEs.

Referenced CVEs

CVE	CSIRTS overview	External
CVE-2026-42828	coverage & exploitation status	NVD · CVE.org

Recent advisories for Windows Projected File

A cluster of recent advisories against the same product widens the attack surface — attackers routinely chain freshly published CVEs on one product, so review these together.

highCVE-2026-42837: Windows Projected File System Elevation of Privilege Vulnerabilitymsrc · 2026-06-09