EUVD-2026-43875
GHSA-2qjv-rvcr-g343
Severity by source
AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Local privilege escalation from an existing low-priv foothold (AV:L, PR:L) with no user interaction and low complexity, yielding full SYSTEM-level C/I/A impact.
Primary rating from Vendor (microsoft).
CVSS VectorVendor: microsoft
Lifecycle Timeline
2DescriptionCVE.org
Use after free in Windows Application Model allows an authorized attacker to elevate privileges locally.
AnalysisAI
Local privilege escalation in the Windows Application Model (the subsystem underlying UWP/packaged app lifecycle and activation) lets an authorized attacker with an existing low-privileged foothold gain SYSTEM-level control by triggering a use-after-free memory-corruption condition. All supported Windows client and server builds from Windows 10 1607 through Windows 11 26H1 and Windows Server 2016 through Server 2025 are affected. This is a Microsoft-reported flaw with a vendor patch available; there is no public exploit identified at time of analysis and it is not on CISA KEV.
Technical ContextAI
The root cause is CWE-416 (Use After Free): the Windows Application Model component frees a heap object but retains and later dereferences a dangling pointer, allowing an attacker who controls the reallocated memory to corrupt kernel/service state and redirect execution. The Application Model governs packaged (UWP/MSIX) application identity, activation, background tasks and lifecycle management, and runs with elevated privileges to broker these operations, which is why a memory-safety bug there yields privilege elevation rather than just a crash. The affected surface per CPE spans Windows 10 (1607, 1809, 21H2, 22H2), Windows 11 (24H2, 25H2, 26H1), and Windows Server 2016/2019/2022/2025 including Server Core installations, indicating shared code across the entire supported Windows family. Note the vendor tags also list 'Denial Of Service,' consistent with a use-after-free that can crash the component if exploitation only corrupts memory without achieving control.
RemediationAI
Patch available per vendor advisory: apply the Microsoft security update for your specific Windows SKU as published in the MSRC guidance at https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-50331, which lists the exact fixed KB/build per version. Because this is a local elevation-of-privilege bug with no documented configuration workaround, patching is the only reliable fix; deploy it through Windows Update, WSUS, or your endpoint management pipeline and prioritize multi-user, RDP/session-host, and terminal-server systems where untrusted low-privileged users share a host. Until the update is applied, reduce exposure by limiting interactive and remote-desktop logon rights to trusted users, enforcing application allow-listing (e.g. WDAC/AppLocker) to hinder delivery of an exploit binary, and monitoring for abnormal crashes or child processes of Application Model / packaged-app broker services - these are compensating controls only and do not remove the vulnerability. No exact fixed version string was provided in the input beyond the per-SKU advisory, so confirm the specific KB number from the MSRC page rather than assuming one.
More in Windows Server 2016
View allWindows MSHTML component contains a remote code execution vulnerability that allows attackers to craft malicious ActiveX
<p>A remote code execution vulnerability exists when the Windows Print Spooler service improperly performs privileged fi
Windows MSDT (Microsoft Support Diagnostic Tool) allows remote code execution when called via the ms-msdt URL protocol f
The SMBv1 server in Microsoft Windows Vista SP2; Windows Server 2008 SP2 and R2 SP1; Windows 7 SP1; Windows 8.1; Windows
The Windows VBScript engine contains a remote code execution vulnerability in object handling that allows full system co
Windows Print Spooler Remote Code Execution Vulnerability. Rated high severity (CVSS 7.8), this vulnerability is no auth
The Win32k kernel-mode driver in Windows Vista through Windows Server 2016 allows local privilege escalation, exploited
Windows Search Remote Code Execution Vulnerability. Rated high severity (CVSS 7.5), this vulnerability is remotely explo
Denial of service against HTTP/2 server implementations allows remote unauthenticated attackers to exhaust server resour
Windows Kernel contains a TOCTOU race condition vulnerability allowing local privilege escalation, exploited by the OilR
An elevation of privilege vulnerability exists in Windows when the Win32k component fails to properly handle objects in
An elevation of privilege vulnerability exists in Windows when the Win32k component fails to properly handle objects in
Same weakness CWE-416 – Use After Free
View allSame technique Denial Of Service
View allShare
External POC / Exploit Code
Leaving vuln.today