Windows Exploitation Techniques: Dangling COM Object Registrations
MentionsMicrosoftMicrosoft Windows
This short blog post is about abusing a privilege escalation bug that Microsoft recently fixed in Windows, CVE-2026-66804, that I and 14 others reported. This issue is an incomplete fix for CVE-2026-50343, a bug dubbed “Dark Elevator” by Calif. The root cause of the bug was a dangling COM object registration for the CrossDevice COM object with the CLSID {E9F83CF2-E0C0-4CA7-AF01-E90C70BEF496}.
Summary from Google Project Zero.
Explained
The technology and terms in this story. Learn more
- AttackPrivilege escalationGoing from limited access to more powerful access, such as from a normal user to administrator.
- ConceptExploitCode or a technique that turns a software flaw into something an attacker can actually use.
- ConceptCVE · Common Vulnerabilities and ExposuresThe public ID system for vulnerabilities, such as CVE-2026-12345, so everyone means the same bug.
Why it was possible
The weaknesses behind this story's CVEs, from each CVE Record.
Vulnerabilities in this story
Severity and exploitation facts from NVD, FIRST, and CISA.