HTTP Request Smuggling Vulnerability in .NET Framework
CVE-2026-62899

5.9MEDIUM

Key Information:

Vendor

Microsoft
Status
.net 10.0
.net 8.0
.net 9.0
Microsoft Visual Studio 2022 Version 17.14
Vendor
CVE Published:
11 August 2026

What is CVE-2026-62899?

A vulnerability exists in the .NET Framework due to inconsistent handling of HTTP requests, which may allow an unauthorized attacker to exploit the system and bypass security features designed to protect web applications and services over the network. This flaw can lead to potential unauthorized access and data exposure, highlighting the importance of applying necessary patches promptly.

Affected Version(s)

.NET 10.0 10.0.0 < 10.0.11

.NET 8.0 8.0.0 < 8.0.30

.NET 9.0 9.0.0 < 9.0.19

References

https://msrc.microsoft.com/update-guide/vulnerability/CVE...
vendor-advisorypatch

CVSS V3.1

Score:
5.9
Severity:
MEDIUM
Confidentiality:
High
Integrity:
None
Availability:
High
Attack Vector:
Network
Attack Complexity:
High
Privileges Required:
None
User Interaction:
None
Scope:
Unchanged

Timeline

  • Vulnerability published

  • Vulnerability Reserved

.