ASP.NET Core Elevation of Privilege Vulnerability
CVE-2026-114148
Summary
Out-of-bounds write in .NET allows an unauthorized attacker to elevate privileges over a network.
Products covered
.NET 8.0 installed on Windows
.NET 8.0 installed on Linux
.NET 8.0 installed on Mac OS
.NET 9.0 installed on Windows
.NET 9.0 installed on Linux
.NET 9.0 installed on Mac OS
.NET 10.0 installed on Windows
.NET 10.0 installed on Linux
Show 11 more products
.NET 10.0 installed on Mac OS
.NET 11.0 installed on Windows
.NET 11.0 installed on Linux
.NET 11.0 installed on Mac OS
Microsoft Visual Studio 2019 version 16.11
Microsoft Visual Studio 2022 version 17.14
Microsoft Visual Studio 2026 version 18.11
Microsoft Visual Studio 2026 version 18.12
PowerShell 7.6
PowerShell 7.5
PowerShell 7.4
Remediation
Release Notes Brotli decompression is not enabled by default in an out-of-the-box .NET or ASP.NET Core install. Applications must manually opt in to ASP.NET Core request decompression or HttpClient response decompression, or they must manually invoke the Brotli decompression APIs provided by .NET. Install KB5133964. Install KB5133965. Install KB5133966.
Vendor-listed fixes
8.0.427
9.0.320
10.0.403
11.0.100-rc.3.26522.148
16.11.61
17.14.43
18.11.2
18.12 Insiders 3
Show 3 more fixes
7.6.9
7.5.13
7.4.22
CVEs in this advisory 1
Updates
- Published by Microsoft Security Response Center
The publication date reported by the vendor.
- Added to SecurityAlert
We collected the advisory from the official source.