Windows Overlay Filter CVE-2026-50435

Exploitation requires the attacker to already have valid low-privileged local access to the target host (CVSS PR:L), matching a local attack vector (AV:L) - this is not remotely reachable and cannot be triggered by an unauthenticated network attacker. No user interaction is needed (UI:N) and attack complexity is low (AC:L), so once a low-privilege foothold exists, escalation is straightforward. The affected code path is the Windows Overlay Filter (WOF) driver, present by default across the listed Windows 10/11 and Windows Server builds, so no unusual non-default feature toggle is indicated by the available data; the primary limiting factor is the prerequisite of prior local code execution as an authenticated low-privileged user.

The CVSS 3.1 base score of 7.8 (AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H) describes a locally exploitable, low-complexity privilege escalation that requires the attacker to already hold low-level privileges on the host but needs no user interaction. This is a classic second-stage / post-compromise escalation primitive rather than an initial-access remote flaw - real-world priority is driven by how commonly the attacker already has a foothold. No EPSS score and no SSVC decision data were provided in the input, so probabilistic exploitation likelihood cannot be quantified here. The vulnerability is not in CISA KEV and no POC is referenced, so there is no evidence of active exploitation or public exploit code at this time. Despite the lack of exploitation signals, the extremely wide affected footprint and the kernel-level HIGH triple impact make this a meaningful patch-cycle priority, especially on multi-user, RDP, or shared server hosts where low-privileged local access is realistic.

An attacker who has already gained low-privileged access to a Windows host - for example a standard user session on a Remote Desktop server or code execution from a low-integrity foothold - invokes the Windows Overlay Filter with crafted input that triggers the out-of-bounds read in kernel context. By leveraging the resulting memory disclosure or corruption they escalate to SYSTEM-level privileges. No user interaction is required, and no public POC or exploit code is identified at time of analysis.