Microsoft Windows Camera Frame Server Monitor: Heap-based buffer overflow allows privilege escalation

Summary

A heap-based buffer overflow in the Windows Camera Frame Server Monitor allows an authorized local attacker with low privileges to elevate privileges to a higher level. Successful exploitation would give the attacker high impact on confidentiality, integrity and availability of the affected system. The attacker needs local access and a valid low-privileged account; the vulnerability is not directly reachable from the internet. CISA SSVC data reports no known exploitation and no automatable exploitation.

Affected

• Windows 10 Version 21H2 before 10.0.19044.7807
• Windows 10 Version 22H2 before 10.0.19045.7807
• Windows 11 Version 23H2 before 10.0.22631.7652
• Windows 11 Version 24H2 before 10.0.26100.9711
• Windows 11 Version 25H2 before 10.0.26200.9711
• Windows 11 Version 26H1 before 10.0.28000.3231
• Windows 11 Version 26H2 before 10.0.26300.9711
• Windows Server 2022 before 10.0.20348.5761
• Windows Server 2025 (including Server Core) before 10.0.26100.33650

Fixed in

• Apply the Microsoft security update for the October 2026 release that brings the build to the versions listed above or later.
• Named cumulative updates (per Tenable listings, to be verified on the MSRC page): KB5126646 (Windows Server 2025), KB5126653 (Windows 11 version 23H2), KB5126655 (Windows Server 2022).
• No KB for Windows 10 21H2 or 22H2 was found in the research.

Workaround

Unknown.

Exploitation

• No known exploitation in the wild found.
• No public proof-of-concept found.
• Not listed in CISA KEV at the time of research.
• CISA SSVC: exploitation none, automatable no, technical impact total.

Our recommendation

• Install the October 2026 cumulative update on all affected Windows systems, prioritising multi-user systems, terminal servers and shared hosts.
• Check whether Windows 10 21H2 or 22H2 machines are still supported; Windows 10 21H2 is out of mainstream servicing and needs Extended Security Updates for fixes.
• Verify the affected build numbers and KB details against the Microsoft Security Update Guide before rollout.
• Monitor for suspicious local privilege escalation activity after phishing or malware incidents.

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-2026-83753 msrc.microsoft.com
• OpenCVE: CVE-2026-83753 app.opencve.io
• Vulners MS mirror: CVE-2026-83753 vulners.com
• Vulners Rapid7 (EPSS data): CVE-2026-83753 vulners.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 2 Nov 2026, 03:09.