Executive brief
ASP.NET Core is a popular framework used by developers to build modern web applications and services. A security flaw in how the framework verifies digital signatures could allow an unauthorized person to gain higher-level permissions on a web server over the internet. This could lead to unauthorized access to sensitive data or the ability to perform administrative actions without proper credentials.
Technical details
A privilege escalation vulnerability exists in ASP.NET Core due to improper verification of cryptographic signatures (CWE-347). The flaw allows a remote, unauthenticated attacker to bypass security checks by providing a specially crafted signature that the system incorrectly validates. Successful exploitation enables the attacker to gain elevated privileges within the context of the application. The vulnerability affects ASP.NET Core 10.0 (versions prior to 10.0.7) and Visual Studio 2026 version 18.5 (versions prior to 18.5.2). Microsoft has released security updates to address this issue.
Affected products
- Microsoft ASP.NET Core 10.0 10.0.0 to 10.0.6
- Microsoft Visual Studio 2026 version 18.5 18.5.0 to 18.5.1
Timeline
- 2026-04-21: disclosed: Initial disclosure by Microsoft and Red Hat
- 2026-04-21: advisory: NVD published the CVE record
- 2026-06-27: other: Last modified date in NVD record