Windows Event Collector Service: Use-after-free privilege escalation

Summary

A use-after-free flaw (CWE-416, CWE-362) in the Windows Event Collector Service allows an authorized attacker to elevate privileges over the network. The attacker needs a valid low-privileged account on a reachable host, and attack complexity is high. Successful exploitation could fully affect confidentiality, integrity and availability of the host. Microsoft rates the CVSS 3.1 base score at 7.5.

Affected

• Windows 10 Version 1607 and Windows Server 2016 (including Server Core): builds 10.0.14393.0 to before 10.0.14393.9688
• Windows 10 Version 1809 and Windows Server 2019 (including Server Core): builds 10.0.17763.0 to before 10.0.17763.9487
• Windows 10 Version 21H2: builds 10.0.19044.0 to before 10.0.19044.7846
• Windows 10 Version 22H2: builds 10.0.19045.0 to before 10.0.19045.7846
• Windows 11 Versions 23H2, 24H2, 25H2, 26H1 and 26H2 and Windows Server 2022: see the CVE record for the exact build ranges

Fixed in

• Fixed builds per CVE record: 10.0.14393.9688 (Windows 10 1607, Server 2016), 10.0.17763.9487 (1809, Server 2019), 10.0.19044.7846 (21H2), 10.0.19045.7846 (22H2), 10.0.22631.7711 (Windows 11 23H2), 10.0.26100.9974 (Windows 11 24H2), 10.0.26200.9974 (Windows 11 25H2), 10.0.28000.3501 (Windows 11 26H1), 10.0.26300.9974 (Windows 11 26H2), 10.0.20348.5870 (Server 2022)
• Update KB numbers: Unknown. Verify in the MSRC advisory.

Workaround

Unknown.

• If Windows Event Forwarding is not used, disable the Windows Event Collector service and restrict the related management ports to trusted hosts. Test first, as log collection may stop.

Exploitation

• CISA SSVC assessment: exploitation none, not automatable.
• No public proof of concept and no in-the-wild exploitation found at the time of research.
• MSRC exploitability data was not verified. Recheck MSRC and the CISA KEV catalogue.

Our recommendation

• Patch affected Windows 10 and Windows Server systems in the next update cycle, once the KB numbers are confirmed in MSRC.
• Check whether Windows 10 1607, 1809 and 21H2 are still supported and plan upgrades where needed.
• Inventory where the Windows Event Collector service runs and prioritise servers used for event forwarding.
• Monitor affected hosts for unusual privilege escalation.

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

• CVE.org record CVE-2026-112793 (Microsoft CNA) www.cve.org
• MSRC Security Update Guide CVE-2026-112793 msrc.microsoft.com
• Action1 Patch Tuesday November 2026 (secondary) www.action1.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, 05:58.