Hackers exploited Sitecore zero-day flaw to deploy backdoors
Threat actors have been exploiting a zero-day vulnerability in legacy Sitecore deployments to deploy WeepSteel reconnaissance malware. The flaw, tracked under CVE-2025-53690, is a ViewState deserialization vulnerability caused by the inclusion of a sample ASP.NET machine key in pre-2017 Sitecore guides. Some customers reused this key in production, allowing attackers with knowledge of the key to craft valid, but malicious '_VIEWSTATE' payloads that tricked the server into deserializing and exe