VYPR
High severityNVD Advisory· Published Feb 13, 2024· Updated May 3, 2025

.NET Denial of Service Vulnerability

CVE-2024-21386

Description

.NET Denial of Service Vulnerability

AI Insight

LLM-synthesized narrative grounded in this CVE's description and references.

A denial-of-service vulnerability in ASP.NET Core SignalR allows a malicious client to crash the server by sending crafted requests.

Vulnerability

Description

CVE-2024-21386 is a denial-of-service vulnerability in ASP.NET Core applications that use SignalR. The root cause lies in how the SignalR server processes certain client requests; a malicious client can trigger an unhandled condition that leads to a server crash, resulting in a denial of service [1]. The vulnerability affects .NET 6.0 (up to 6.0.26), .NET 7.0 (up to 7.0.15), and .NET 8.0 (up to 8.0.1) [1].

Exploitation

An attacker does not need authentication to trigger this vulnerability; any client that can connect to a vulnerable SignalR hub can send specially crafted messages that exploit the flaw [1]. The attack is network-based and requires no special privileges, making it relatively easy for a remote attacker to disrupt service. Microsoft has stated that no mitigating factors exist for this issue [1].

Impact

Successful exploitation allows an attacker to cause the ASP.NET Core server to crash, leading to a temporary denial of service for all users of the affected application. The impact is limited to availability; there is no risk of data compromise or code execution [1].

Mitigation

Microsoft has released patched versions of the affected packages [1]. Developers should update their applications to .NET 6.0.27, .NET 7.0.16, or .NET 8.0.2 (or later) to remediate the vulnerability [1]. No workarounds have been provided. The advisory is also tracked under GHSA-g74q-5xw3-j7q9 [1].

AI Insight generated on May 20, 2026. Synthesized from this CVE's description and the cited reference URLs; citations are validated against the source bundle.

Affected packages

Versions sourced from the GitHub Security Advisory.

PackageAffected versionsPatched versions
Microsoft.AspNetCore.App.Runtime.linux-armNuGet
< 6.0.276.0.27
Microsoft.AspNetCore.App.Runtime.linux-arm64NuGet
< 6.0.276.0.27
Microsoft.AspNetCore.App.Runtime.linux-musl-armNuGet
< 6.0.276.0.27
Microsoft.AspNetCore.App.Runtime.linux-musl-arm64NuGet
< 6.0.276.0.27
Microsoft.AspNetCore.App.Runtime.linux-musl-x64NuGet
< 6.0.276.0.27
Microsoft.AspNetCore.App.Runtime.linux-x64NuGet
< 6.0.276.0.27
Microsoft.AspNetCore.App.Runtime.osx-arm64NuGet
< 6.0.276.0.27
Microsoft.AspNetCore.App.Runtime.osx-x64NuGet
< 6.0.276.0.27
Microsoft.AspNetCore.App.Runtime.win-armNuGet
< 6.0.276.0.27
Microsoft.AspNetCore.App.Runtime.win-arm64NuGet
< 6.0.276.0.27
Microsoft.AspNetCore.App.Runtime.win-x64NuGet
< 6.0.276.0.27
Microsoft.AspNetCore.App.Runtime.win-x86NuGet
< 6.0.276.0.27
Microsoft.AspNetCore.App.Runtime.linux-armNuGet
>= 7.0.0, < 7.0.167.0.16
Microsoft.AspNetCore.App.Runtime.linux-arm64NuGet
>= 7.0.0, < 7.0.167.0.16
Microsoft.AspNetCore.App.Runtime.linux-musl-armNuGet
>= 7.0.0, < 7.0.167.0.16
Microsoft.AspNetCore.App.Runtime.linux-musl-arm64NuGet
>= 7.0.0, < 7.0.167.0.16
Microsoft.AspNetCore.App.Runtime.linux-musl-x64NuGet
>= 7.0.0, < 7.0.167.0.16
Microsoft.AspNetCore.App.Runtime.linux-x64NuGet
>= 7.0.0, < 7.0.167.0.16
Microsoft.AspNetCore.App.Runtime.osx-arm64NuGet
>= 7.0.0, < 7.0.167.0.16
Microsoft.AspNetCore.App.Runtime.osx-x64NuGet
>= 7.0.0, < 7.0.167.0.16
Microsoft.AspNetCore.App.Runtime.win-armNuGet
>= 7.0.0, < 7.0.167.0.16
Microsoft.AspNetCore.App.Runtime.win-arm64NuGet
>= 7.0.0, < 7.0.167.0.16
Microsoft.AspNetCore.App.Runtime.win-x64NuGet
>= 7.0.0, < 7.0.167.0.16
Microsoft.AspNetCore.App.Runtime.win-x86NuGet
>= 7.0.0, < 7.0.167.0.16
Microsoft.AspNetCore.App.Runtime.linux-armNuGet
>= 8.0.0, < 8.0.28.0.2
Microsoft.AspNetCore.App.Runtime.linux-arm64NuGet
>= 8.0.0, < 8.0.28.0.2
Microsoft.AspNetCore.App.Runtime.linux-musl-armNuGet
>= 8.0.0, < 8.0.28.0.2
Microsoft.AspNetCore.App.Runtime.linux-musl-arm64NuGet
>= 8.0.0, < 8.0.28.0.2
Microsoft.AspNetCore.App.Runtime.linux-musl-x64NuGet
>= 8.0.0, < 8.0.28.0.2
Microsoft.AspNetCore.App.Runtime.linux-x64NuGet
>= 8.0.0, < 8.0.28.0.2
Microsoft.AspNetCore.App.Runtime.osx-arm64NuGet
>= 8.0.0, < 8.0.28.0.2
Microsoft.AspNetCore.App.Runtime.osx-x64NuGet
>= 8.0.0, < 8.0.28.0.2
Microsoft.AspNetCore.App.Runtime.win-armNuGet
>= 8.0.0, < 8.0.28.0.2
Microsoft.AspNetCore.App.Runtime.win-arm64NuGet
>= 8.0.0, < 8.0.28.0.2
Microsoft.AspNetCore.App.Runtime.win-x64NuGet
>= 8.0.0, < 8.0.28.0.2
Microsoft.AspNetCore.App.Runtime.win-x86NuGet
>= 8.0.0, < 8.0.28.0.2

Affected products

52

Patches

0

No patches discovered yet.

Vulnerability mechanics

AI mechanics synthesis has not run for this CVE yet.

References

4

News mentions

0

No linked articles in our index yet.