CVE-2026-56164

This vulnerability lets a remote attacker “skip the front door” (no login required) and gain higher control inside your SharePoint server. Think of it like leaving a keyhole unprotected—someone who can reach your building can potentially reach offices they shouldn’t. CISA reports this is being used in real attacks, not just theoretical testing.

This matters if you run Microsoft SharePoint Server—specifically Microsoft SharePoint Enterprise Server 2016, Microsoft SharePoint Server 2019, Microsoft SharePoint Server Subscription Edition, or sharepoint server. The risk is for systems reachable over the network, and it does not require a login or user action. It is a priority when your SharePoint is network-accessible (for example, reachable from the internet or otherwise reachable by attackers).

This is RED because CISA added CVE-2026-56164 to its Known Exploited Vulnerabilities list and exploitation has been reported as active in the wild. Attackers are using it to bypass authentication and gain elevated privileges remotely, so attackers can move quickly once they find an exposed SharePoint.