CVE-2026-62898 Microsoft QUIC Information Disclosure Vulnerability
An unauthorized attacker can disclose information over the network via a use-after-free flaw in the Microsoft QUIC library.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-62898?
CVE-2026-62898 is a high-severity use after free vulnerability in Microsoft .Net, published on 11 Aug 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
Use after free in Microsoft QUIC allows an unauthorized attacker to disclose information over a network.
Weakness: CWE-416
Which versions are affected by CVE-2026-62898?
20 open source packages ship an affected version, including Microsoft.NETCore.App.Runtime.win-arm64, dotnet and dotnet-sdk. It affects 3 products.
| Package | Affected | Fixed in |
|---|---|---|
Microsoft.NETCore.App.Runtime.win-arm64 NuGet | From 10.0.0 | 10.0.11 |
Microsoft.NETCore.App.Runtime.win-arm64 NuGet | From 10.0.0 | 10.0.11 |
Microsoft.NETCore.App.Runtime.win-arm64 NuGet | From 8.0.0 | 8.0.30 |
Microsoft.NETCore.App.Runtime.win-arm64 NuGet | From 8.0.0 | 8.0.30 |
Microsoft.NETCore.App.Runtime.win-arm64 NuGet | From 9.0.0 | 9.0.19 |
Microsoft.NETCore.App.Runtime.win-arm64 NuGet | From 9.0.0 | 9.0.19 |
14 more packages
dotnet Bitnami | From 8.0.0 | 8.0.30, 9.0.19, 10.0.11 |
dotnet-sdk Bitnami | From 8.0.0 | 8.0.30, 9.0.19, 10.0.11 |
Microsoft.NETCore.App.Runtime.win-x64 NuGet | From 10.0.0 | 10.0.11 |
Microsoft.NETCore.App.Runtime.win-x64 NuGet | From 10.0.0 | 10.0.11 |
Microsoft.NETCore.App.Runtime.win-x64 NuGet | From 8.0.0 | 8.0.30 |
Microsoft.NETCore.App.Runtime.win-x64 NuGet | From 8.0.0 | 8.0.30 |
Microsoft.NETCore.App.Runtime.win-x64 NuGet | From 9.0.0 | 9.0.19 |
Microsoft.NETCore.App.Runtime.win-x64 NuGet | From 9.0.0 | 9.0.19 |
Microsoft.NETCore.App.Runtime.win-x86 NuGet | From 10.0.0 | 10.0.11 |
Microsoft.NETCore.App.Runtime.win-x86 NuGet | From 10.0.0 | 10.0.11 |
Microsoft.NETCore.App.Runtime.win-x86 NuGet | From 8.0.0 | 8.0.30 |
Microsoft.NETCore.App.Runtime.win-x86 NuGet | From 8.0.0 | 8.0.30 |
Microsoft.NETCore.App.Runtime.win-x86 NuGet | From 9.0.0 | 9.0.19 |
Microsoft.NETCore.App.Runtime.win-x86 NuGet | From 9.0.0 | 9.0.19 |
Products include Microsoft .Net, Microsoft Visual Studio 2022, Microsoft Visual Studio 2026.
How do I fix CVE-2026-62898?
Upgrade Microsoft.NETCore.App.Runtime.win-arm64 to a fixed version for your release line: 10.0.11, 8.0.30 or 9.0.19.
Upgrade to the fixed version. These bugs are found with fuzzing and sanitisers and avoided by memory-safe languages. More about Use after free.
Is CVE-2026-62898 being exploited?
There is no known exploitation of CVE-2026-62898 in the wild and no public exploit code.
Other vulnerabilities in Microsoft .Net
- CVE-2024-43498 .NET and Visual Studio Remote Code Execution Vulnerability
- CVE-2024-0057 NET, .NET Framework, and Visual Studio Security Feature Bypass Vulnerability
- CVE-2026-96957 .NET Security Feature Bypass Vulnerability
- CVE-2026-69439 .NET and Visual Studio Elevation of Privilege Vulnerability
- CVE-2026-71328 .NET and Visual Studio Remote Code Execution Vulnerability
Sources
Also known as BELL-CVE-2026-62898, BIT-dotnet-2026-62898, BIT-dotnet-sdk-2026-62898, GHSA-c494-m2fq-59mx, MINI-6p24-m498-ppr2, MINI-fwxj-h5q3-xvpj and 1 more.