Windows ProjFS CVE-2026-96857

Requires the attacker to already be an authenticated local user (PR:L) on a Windows system where the Projected File System (ProjFS) component is active - ProjFS is the virtualization filesystem driver used by features such as Windows Containers and VFS-for-Git-style providers, so exposure is greatest where a ProjFS provider is in use. Exploitation is local only (AV:L), needs no user interaction (UI:N), and is not automatable per CISA SSVC, which limits it to manual abuse by someone with an existing foothold; it cannot be triggered remotely or without valid credentials. Impact is confined to information disclosure (C:H, I:N, A:N).

This is a moderate-severity local information disclosure flaw (CVSS 5.5) whose signals are internally consistent and point to low real-world urgency. The CVSS vector (AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N) requires local access and existing low privileges, limiting the attack surface to users who can already authenticate to the host; the only impact is confidentiality (C:H), with no integrity or availability effect. CISA's SSVC decision framework corroborates low priority: Exploitation=none, Automatable=no, Technical Impact=partial. No EPSS score, KEV listing, or public POC was provided, and there is no public exploit identified at time of analysis - so there is no evidence of widespread or targeted exploitation. This is best characterized as a routine patch-cycle item rather than an emergency: a genuine confidentiality weakness, but gated behind local authenticated access and not automatable, making it a low priority relative to remote or wormable flaws. No conflicting signals were detected; the main gap is the absence of a detailed Microsoft technical writeup beyond the MSRC advisory reference.

An attacker who already has a low-privileged interactive or authenticated session on a Windows host abuses the Projected File System (ProjFS) component to read files or directory contents that should be isolated from them, disclosing sensitive data belonging to other users or the system. Because the CVSS vector is AV:L/AC:L and Automatable=no, exploitation is hands-on-keyboard and local, not remote or mass-scalable. No public exploit code was identified at time of analysis.