‘Highest Ever’ Severity Score Assigned by Microsoft to ASP.NET Core Vulnerability

‘Highest Ever’ Severity Score Assigned by Microsoft to ASP.NET Core Vulnerability

Microsoft released patches for a critical vulnerability (CVE-2025-55315) in ASP.NET Core that could enable attackers to bypass security controls and hijack user sessions. This HTTP request smuggling flaw primarily impacts Kestrel web server applications and has a CVSS score of 9.9, highlighting its severity. #CVE-2025-55315 #ASP.NETCore #Kestrel #RequestSmuggling

Keypoints

  • The vulnerability is an HTTP request smuggling flaw affecting ASP.NET Core’s Kestrel web server.
  • Exploitation can lead to bypassing security features, credential hijacking, and information leaks.
  • Microsoft issued patches for multiple ASP.NET Core versions and Visual Studio updates to address the issue.
  • Attackers could use the flaw to perform injection attacks or elevate privileges based on application setup.
  • The CVSS score of 9.9 indicates the vulnerability’s critical severity and potential impact.

Read More: https://www.securityweek.com/highest-ever-severity-score-assigned-by-microsoft-to-asp-net-core-vulnerability/