‘Unlimited Attack Vectors’—All Windows Versions At Risk From New Flaw

InnovationCybersecurity‘Unlimited Attack Vectors’—All Windows Versions At Risk From New FlawByDavey Winder,Senior Contributor.Forbes contributors publish independent expert analyses and insights. Davey Winder is a veteran cybersecurity writer, hacker and analyst.Follow AuthorApr 28, 2026, 09:46am EDT--:-- / --:--This voice experience is generated by AI. Learn more.This voice experience is generated by AI. Learn more.PhantomRPC Microsoft Windows vulnerability remains unpatched.gettyMicrosoft has failed to patch a security vulnerability affecting Windows users, with the ability to enable privilege escalation, and for which the researcher behind the discovery warned: “the number of potential attack vectors is effectively unlimited.” Here’s what you need to know about the PhantomRPC vulnerability, seated at the heart of the Windows Remote Procedure Call mechanism, and which Kaspersky researcher Haidar Kabibo said is “likely in all Windows versions.”ForbesDangerous Fake Microsoft Windows Update Confirmed—Do Not DownloadBy Davey WinderThe Windows PhantomRPC Vulnerability And Why Isn’t It Patched YetMicrosoft has a heck of a job on its hands when it comes to the sheer number of security vulnerabilities that affect the Windows operating system, of that there is no doubt. On the whole, it does a good job in dealing with them as they are discovered. Sometimes, however, the response to security researchers can be best described as underwhelming, as was the case when one such researcher dropped a zero-day in frustration recently. Now there’s another case that has left some cybersecurity experts confused at the lack of reaction by way of a patch to mitigate a newly discovered vulnerability that impacts the Windows RPC architecture.Known as PhantomPRC, the vulnerability “enables processes with impersonation privileges to elevate their permissions to SYSTEM level,” Kaspersky’s Kabibo said. RPC is the Windows tech to provide the communication between two processes, enabling one to...