CVE-2026-69304: ASP.NET Core Denial of Service Vulnerability

Overview

Severity

Medium (CVSS 5.9)

CVSS Vector

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H/E:U/RL:O/RC:C

Category

Denial of Service

Exploit Status

Not Exploited

Exploitation Likelihood

Less Likely

Patch Tuesday

2026-Sep

Released

2026-09-08

Description

Improper handling of highly compressed data (data amplification) in ASP.NET Core allows an unauthorized attacker to deny service over a network.

Affected Products (9)

Developer Tools

• ASP.NET Core 11.0
• .NET 10.0 installed on Windows
• .NET 9.0 installed on Windows
• .NET 8.0 installed on Windows
• Microsoft Visual Studio 2026 version 18.9
• Microsoft Visual Studio 2022 version 17.14
• ASP.NET Core 9.0
• ASP.NET Core 10.0
• ASP.NET Core 8.0

Security Updates (6)

• Security Update
• 5126106
• 5126105
• 5126104
• Release Notes
• Release Notes

Acknowledgments

Anonymous, محمد السيد عثمان محمود القصاص

Revision History

• 2026-09-08: Information published.