EUVD-2026-44003
GHSA-mvwv-cxfc-w333
Severity by source
AV:P/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
Physical USB insertion required (AV:P, AC:H for race condition timing); no OS authentication needed for a physically present attacker (PR:N); full local system compromise on successful exploitation (C/I/A:H).
Primary rating from Vendor (microsoft).
CVSS VectorVendor: microsoft
Lifecycle Timeline
2DescriptionCVE.org
Use after free in Windows USB Print Driver allows an unauthorized attacker to elevate privileges with a physical attack.
AnalysisAI
Privilege escalation via use-after-free in the Windows USB Print Driver affects Windows 11 (versions 24H2, 25H2, 26H1) and Windows Server 2025, requiring physical access to exploit. An attacker with hands-on access to a target machine can trigger a memory corruption condition through the USB print subsystem to achieve full local privilege escalation - High confidentiality, integrity, and availability impact per CVSS. No public exploit code has been identified at time of analysis, and this vulnerability is not listed in the CISA KEV catalog.
Technical ContextAI
The vulnerability resides in the Windows USB Print Driver component, which handles USB-attached printer enumeration and communication. CWE-416 (Use After Free) describes the root cause: a memory region is freed but a dangling pointer to it remains accessible, and if that memory is reallocated and the stale pointer is later dereferenced, an attacker can control the freed memory contents to redirect execution or corrupt kernel state. Affected CPEs span cpe:2.3:a:microsoft:windows_11_version_24h2, windows_11_version_25h2, windows_11_version_26h1, windows_server_2025, and windows_server_2025_(server_core_installation) - all recent Microsoft OS releases. The CVSS vector AV:P/AC:H confirms the attack requires physical USB port access and a high-complexity exploitation technique, consistent with triggering a precise race condition or use-after-free timing window in driver code handling USB device insertion or print job processing.
RemediationAI
Apply the vendor-released patch from Microsoft, available via the MSRC advisory at https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-55000. The exact patched version number is not independently confirmed from available data - verify via Windows Update or the MSRC bulletin for the specific KB article. As a compensating control where patching is immediately not feasible, restrict physical USB port access on sensitive systems through BIOS/UEFI USB disablement or USB port blockers - note this will also prevent legitimate USB peripherals. Organizations can also deploy endpoint controls (e.g., Windows Defender Application Control, USB device restriction via Group Policy under 'Prevent installation of removable devices') to block USB print device installation. These controls carry the operational trade-off of blocking all USB-attached printers, which may affect productivity. Prioritize patching on publicly accessible machines, shared workstations, and server hardware in facilities with limited physical access controls.
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Same weakness CWE-416 – Use After Free
View allSame technique Denial Of Service
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External POC / Exploit Code
Leaving vuln.today