What’s Vulnerable › Vulnerabilities
CVE-2026-70188: ASP.NET Core Security Feature Bypass Vulnerability
- Severity: critical (CVSS 9.1 v3.1)
- Exploited in the wild: not listed in CISA KEV
- EPSS: 0.9% probability of exploitation in the next 30 days
- Public exploit or detection template: none known
- Published: 2026-10-13 · updated 2026-10-31
- Weakness: CWE-444
Description
Inconsistent interpretation of http requests ('http request/response smuggling') in ASP.NET Core allows an unauthorized attacker to bypass a security feature over a network.
Affected products
- Microsoft ASP.NET Core 10.0: from 10.0 before 10.0.13 — fixed in 10.0.13
- Microsoft ASP.NET Core 11.0: from 11.0 before 11.0.0-rc.2 — fixed in 11.0.0-rc.2
- Microsoft ASP.NET Core 8.0: from 8.0 before 8.0.32 — fixed in 8.0.32
- Microsoft ASP.NET Core 9.0: from 9.0 before 9.0.21 — fixed in 9.0.21
- Microsoft Visual Studio 2026 version 18.10: from 18.10.0 before 18.10.4 — fixed in 18.10.4
- Microsoft Visual Studio 2022 version 17.14: from 17.14.0 before 17.14.42 — fixed in 17.14.42
How to fix
Upgrade to a fixed version: Microsoft ASP.NET Core 10.0 10.0.13; Microsoft ASP.NET Core 11.0 11.0.0-rc.2; Microsoft ASP.NET Core 8.0 8.0.32; Microsoft ASP.NET Core 9.0 9.0.21; Microsoft Visual Studio 2026 version 18.10 18.10.4; Microsoft Visual Studio 2022 version 17.14 17.14.42. Check the vendor advisory for mitigations.
References
Get alerted when CVE-2026-70188 or the next vulnerability affects your stack