Vulnerability GHSA-wr8v-9x5q-ggcm

Executive summary

Microsoft is releasing this security advisory to provide information about a vulnerability in ASP.NET Core. This advisory provides guidance on updating affected applications and components.

SignalR Redis scale-out can mishandle case-mismatched group removal and leave subscriptions in a state that permits persistent resource amplification and denial of service.

Announcement

Announcement for this issue can be found at https://github.com/dotnet/announcements/issues/509

CVSS Details

• Version: 3.1
• Severity: High
• Score: 7.5 (base score)
• Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:U/RL:O/RC:C
• Weakness: CWE-401

Affected Platforms

• Platforms: Windows, Linux, macOS
• Architectures: All

Affected Packages

The tables list affected version ranges and fixed package versions. Runtime and standalone deliveries are listed separately.

8.0 - standalone packages

9.0 - standalone packages

10.0 - standalone packages

11.0 - standalone packages

.NET 8.0 - affected runtime packages

.NET 9.0 - affected runtime packages

.NET 10.0 - affected runtime packages

.NET 11.0 - affected runtime packages

Advisory FAQ

How do I know if I am affected?

Compare the deployed ASP.NET Core runtime and the application's resolved Microsoft.AspNetCore.SignalR.StackExchangeRedis package version with the affected ranges above. Self-contained applications include their own runtime.

How do I fix the issue?

Update both the ASP.NET Core runtime and the Microsoft.AspNetCore.SignalR.StackExchangeRedis package to the applicable patched versions above. Restart affected framework-dependent applications after installing the runtime update. Rebuild and redeploy applications after updating the package; self-contained applications must also be rebuilt with the patched runtime. Updating a machine-wide runtime or SDK alone does not update an application's standalone package references.

Other Information

Reporting Security Issues

If you have found a potential security issue in a supported version of .NET, please report it to the Microsoft Security Response Center (MSRC) via the MSRC Researcher Portal. Further information can be found in the MSRC Report an Issue FAQ.

Security reports made through MSRC may qualify for the Microsoft .NET Bounty. Details of the Microsoft .NET Bounty Program including terms and conditions are at https://aka.ms/corebounty.

Support

You can ask questions about this issue on GitHub in the .NET GitHub organization. The main repos are located at https://github.com/dotnet/runtime. The Announcements repo ( https://github.com/dotnet/Announcements) will contain this bulletin as an issue and will include a link to a discussion issue. You can ask questions in the linked discussion issue.

Disclaimer

The information provided in this advisory is provided "as is" without warranty of any kind. Microsoft disclaims all warranties, either express or implied, including the warranties of merchantability and fitness for a particular purpose. In no event shall Microsoft Corporation or its suppliers be liable for any damages whatsoever including direct, indirect, incidental, consequential, loss of business profits or special damages, even if Microsoft Corporation or its suppliers have been advised of the possibility of such damages. Some states do not allow the exclusion or limitation of liability for consequential or incidental damages so the foregoing limitation may not apply.

External Links

CVE-2026-114147

Acknowledgements

• 71C4 with ARPSEC
• 71C4

Revisions

V1.0 (November 10, 2026): Advisory published.