Revision Note: V1.0 (November 30, 2015): Advisory published.Summary: Microsoft is aware of unconstrained digital certificates from Dell Inc. for which the private keys were inadvertently disclosed. One of these unconstrained certificates could be used to issue other certificates, impersonate other domains, or sign code. In addition, these certificates could be used to spoof content, perform phishing attacks, or perform man-in-the-middle attacks against Dell customers. This issue affects all supported releases of Microsoft Windows. Microsoft is not currently aware of attacks related to this issue.