A critical authentication bypass vulnerability (CVE-2026-3564, CVSS 9.0) in ConnectWise ScreenConnect allows remote attackers to forge trusted sessions by exploiting improper cryptographic signature verification related to ASP.NET machine keys. The article notes ScreenConnect is widely deployed on-premises by MSPs and IT departments, but specific affected and patched version numbers are not provided in the source material.
ConnectWise has patched a critical vulnerability (CVE-2026-3564) that could enable attackers to hijack ScreenConnect sessions by abusing ASP.NET machine keys to forge trusted authentication. About CVE-2026-3564 The ScreenConnect remote access platform is popular with managed service providers, IT departments, and technology solution providers. They can opt for the cloud-hosted version or can deploy it on their own servers or in their private cloud. CVE-2026-3564 stems from improper verification of cryptographic signature, can be exploited remotely … More → The post Unpatched ScreenConnect servers open to attack (CVE-2026-3564) appeared first on Help Net Security .