Inconsistent interpretation of HTTP requests in Visual Studio and ASP.NET Core - CVE-2026-70188
Published: October 14, 2026
Vulnerability identifier: #VU154629
CSH Severity: High
CVSS v4: 9.3 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-70188
CWE-ID: CWE-444
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to bypass authentication and access protected resources.
The vulnerability exists due to inconsistent interpretation of HTTP requests in ASP.NET Core when processing HTTP/2 requests. A remote attacker can send specially crafted HTTP/2 requests to bypass authentication and access protected resources.
No user interaction is required.
Affected software
Visual Studio
ASP.NET Core
ASP.NET Core
How to mitigate CVE-2026-70188
Install security update from vendor's website.
Visual Studio - update to 17.14.42
ASP.NET Core - addressed in versions 8.0.32, 9.0.21
ASP.NET Core - addressed in versions 8.0.32, 9.0.21