Microsoft Windows: Elevation of privilege in COM+ Event System Service
Summary
The Windows COM+ Event System Service is affected in several Windows 10, Windows 11 and Windows Server versions. An authenticated local user with a low-privileged account can trigger an untrusted pointer dereference and elevate privileges locally. Remote exploitation is not possible according to the CVE record (local attack vector), and CISA SSVC lists exploitation as none. CVSS 3.1 base score is 7.8 (High).
Affected
- Windows 10 Version 1607: below 10.0.14393.0 to < 10.0.14393.9612
- Windows 10 Version 1809: below 10.0.17763.9376
- Windows 10 Version 21H2: below 10.0.19044.7807
- Windows 10 Version 22H2: below 10.0.19045.7807
- Windows 11 Version 23H2: below 10.0.22631.7652
- Windows 11 Version 24H2: below 10.0.26100.9711
- Windows 11 Version 25H2 and 26H2: below 10.0.26200.9711 and 10.0.26300.9711
- Windows 11 Version 26H1: below 10.0.28000.3231
- Windows Server 2012 and 2012 R2 (including Server Core): below 6.2.9200.26434 and 6.3.9600.23470
- Windows Server 2016: below 10.0.14393.9612
Fixed in
- Fixed in Microsoft's October 2026 security update for the listed builds, according to the CNA data.
- The Windows 10 1607 fixed build 10.0.14393.9612 has not been verified on the MSRC product table; confirm it before rollout.
Workaround
- Unknown. The CVE record provides no Microsoft-documented workaround.
- General hardening: run the COM+ Event System Service with the minimum required privileges. This reduces exposure but does not fix the flaw.
Exploitation
- Exploited in the wild: Unknown. No vendor or CISA statement found.
- Public proof of concept: None found.
- Known zero-day status: Unknown.
- EPSS: below 1 percent (very low).
- CISA SSVC: Exploitation none, Automatable no, Technical Impact total.
Our recommendation
- Install the October 2026 Microsoft security update via Windows Update, WSUS or the Microsoft Update Catalog.
- Prioritise shared PCs, terminal servers and older Windows systems, where local accounts are present.
- Upgrade Windows 10 1607 and other end-of-life systems instead of relying on patches, and check Microsoft's lifecycle page.
- Restrict local logon on shared machines, enforce least-privilege accounts and monitor for unexpected privilege changes.
Information from Microsoft (Patch Tuesday October 2026)
- Severity (Microsoft)
- Important
- Impact
- Elevation of privilege – Windows COM+ Event System Service
- Status on Patch Tuesday
- Neither exploited nor publicly disclosed
- Exploitability assessment
- Exploitation less likely
- Product family
- Windows, Windows ESU (Extended Security Updates)
- Updates (KB)
- KB5127648, KB5126651, KB5126655, KB5126657, KB5126646, KB5126653
Public exploits
PoC-in-GitHub, Metasploit and Exploit-DB list nothing for this CVE.
Research sources
- Microsoft Security Update Guide: CVE-2026-96933 msrc.microsoft.com
- OpenCVE: CVE-2026-96933 app.opencve.io
- Vulners CVE list: CVE-2026-96933 vulners.com
- Vulners EUVD-2026-100252 vulners.com
- Anoop C Nair: Microsoft fixes 1411 security vulnerabilities www.anoopcnair.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, 00:38.
Original description (NVD)
Untrusted pointer dereference in Windows COM+ Event System Service allows an authorized attacker to elevate privileges locally.
NVD references (1)
Sources
The tracker combines official, freely usable data sources – updated continuously:
- NVD (NIST) – CVEs, rating (CVSS), affected products
- CISA KEV – vulnerabilities confirmed by CISA as actively exploited
- CISA Vulnrichment – CISA assessment (SSVC) in the official CVE record
- FIRST EPSS – probability of exploitation
- Microsoft MSRC – Patch Tuesday: vulnerabilities, severity, updates
- PoC-in-GitHub – public proof-of-concept repositories
- Metasploit (Rapid7) – modules of the Metasploit Framework
- Exploit-DB (OffSec) – archive of public exploits (links only)
- Patch days: official vendor pages (linked per vendor) (Vendor patch days)
This product uses data from the NVD API but is not endorsed or certified by the NVD. EPSS data © FIRST.org.
Affected? We can help.
We check whether your systems are affected, install updates and close the gap – continuously with the System Health Checker if you wish.