Microsoft Windows Smart Card: Local privilege escalation via uninitialized resource

Summary

A flaw in the Windows Smart Card component uses an uninitialized resource, which allows an authorized attacker to elevate privileges. The attack requires physical access to the affected system and low privileges, such as a standard user account. The main risk is a user or insider with brief physical access to a logged-in or unlocked machine, not remote exploitation over the internet.

Affected

• Windows 10 Version 1607 and Windows Server 2016 (including Server Core): before 10.0.14393.9688
• Windows 10 Version 1809 and Windows Server 2019 (including Server Core): before 10.0.17763.9487
• Windows 10 Version 21H2: before 10.0.19044.7846
• Windows 10 Version 22H2: before 10.0.19045.7846
• Windows 11 Version 23H2: before 10.0.22631.7711
• Windows 11 Version 24H2: before 10.0.26100.9974
• Windows 11 Version 25H2: before 10.0.26200.9974
• Windows 11 Version 26H1: before 10.0.28000.3501
• Windows 11 Version 26H2: before 10.0.26300.9974
• Windows Server 2022: before 10.0.20348.5870

Build numbers are from the CVE record and are provisional until confirmed in the MSRC Security Update Guide.

Fixed in

Install the November 2026 cumulative update for each affected Windows version. KB numbers: Unknown. Check the MSRC Security Update Guide for the exact update per build.

Workaround

Unknown. No vendor workaround is documented. Mitigate by controlling physical access to endpoints, enforcing screen locks, and restricting use of shared or unattended smart card workstations.

Exploitation

• CISA SSVC: exploitation none, automatable no, technical impact total.
• No confirmed in-the-wild exploitation known.
• No public proof of concept found; this CVE is very new.
• CVSS 6.6 (v3.1), AV:P/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.

Our recommendation

• Install the November 2026 Windows cumulative update on all listed systems, prioritizing shared PCs, reception and kiosk machines, and laptops that leave the office.
• Verify the affected build numbers and KB numbers in the MSRC Security Update Guide before planning the rollout.
• Enforce screen locks and limit physical access to endpoints, especially those used with smart cards.
• Review which accounts are low-privileged users on these systems and monitor for unusual privilege changes.

Public exploits iAttack code is publicly available (PoC on GitHub, Metasploit or Exploit-DB).

PoC-in-GitHub, Metasploit and Exploit-DB list nothing for this CVE.

Research sources

• Microsoft Security Update Guide: CVE-2026-119383 msrc.microsoft.com
• CVE Record: CVE-2026-119383 www.cve.org
• Strix.ai: CVE-2026-119383 www.strix.ai
• Senserva KB summary 5132059 senserva.com

Researched and written up in English and German by an AI (Claude by Anthropic) based on NVD, CISA, EPSS and the sources listed. The vendor information is authoritative. Researched on 11 Nov 2026, 11:44.