Inconsistent interpretation of HTTP requests in Microsoft products - CVE-2026-62899

Vulnerability details

The vulnerability allows a remote attacker to bypass a security feature.

The vulnerability exists due to inconsistent interpretation of http requests in .NET when handling http requests. A remote attacker can send crafted http requests to bypass a security feature.

Successful exploitation requires the target system to be configured in a specific manner and knowledge of that setup.

Affected software

How to mitigate CVE-2026-62899

External References

• https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2026-62899
• https://support.microsoft.com/help/5122106

Related Security Bulletins

• Multiple vulnerabilities in Microsoft .NET Framework