Time to Bail · Boarding pass
Act. You can stay.
.NET 8 on Lambda is deprecated November 10, 2026. Updates to these functions are blocked from August 31, 2027.[1]
Act means: change a setting or plan before the date. You can stay.
AWS Lambda .NET 8 runtime deprecated November 10, 2026
AWS deprecates the .NET 8 runtime (dotnet8) for Lambda on November 10, 2026. After that it may get no more security patches. Creating functions is blocked from July 29, 2027, and updating them from August 31, 2027.
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Filter by runtime in the Lambda console, or list dotnet8 functions with the AWS CLI in each region.
Build the project for .NET 10 and set the runtime to dotnet10. Update NuGet packages.
Test each function on the new runtime. After August 31, 2027 you cannot update a dotnet8 function.
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Or add the date to your calendar: Apple or Outlook (.ics) · Google Calendar
| Deprecation date | November 10, 2026[1] |
|---|---|
| Runtime | dotnet8 (.NET 8 on Amazon Linux 2023)[1] |
| Creating new functions blocked | July 29, 2027[1] |
| Updating functions blocked | August 31, 2027[1] |
| Container-only .NET runtime | .NET 9 (container image only) is also deprecated November 10, 2026; block dates not scheduled[1] |
| After deprecation | AWS may stop security patches and technical support; you can still invoke your functions[1] |
| In the Lambda console | From the deprecation date you cannot create or update these functions there; the AWS CLI, AWS SAM and CloudFormation still work until the blocks[1] |
| Once updates are blocked | You cannot go back to the deprecated runtime[1] |
| How AWS tells you | Email and Health Dashboard notices at least 180 days before; Trusted Advisor lists the functions[1] |
| Can the dates change? | Yes. AWS says the dates are for planning and subject to change[1] |
| How to list them | aws lambda list-functions --function-version ALL --region us-east-1 --query "Functions[?Runtime=='dotnet8'].FunctionArn" (once per region)[2] |
| Newer .NET runtimes | dotnet10 (.NET 10) until November 14, 2028[1] |
| Functions on .NET 8 | May get no security patches after November 10, 2026; no updates from August 31, 2027[1] |
In the Lambda console you can no longer create or update functions on dotnet8. The AWS CLI, AWS SAM and CloudFormation still work until the blocks. Your functions keep running, but AWS may stop security patches.
dotnet8 functions: aws lambda list-functions --function-version ALL --region us-east-1 --output text --query "Functions[?Runtime=='dotnet8'].FunctionArn". Run it in each region.dotnet10. Test it before you ship.Source: [1] Lambda runtimes (Amazon Web Services) · [2] Retrieve data about Lambda Event Functions that use a deprecated runtime (Amazon Web Services)
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Time to bail on Lambda functions on .NET 8? Act. You can stay. .NET 8 on Lambda is deprecated November 10, 2026. Updates to these functions are blocked from August 31, 2027.
On our scale this is Act: change a setting or plan before the date. You can stay.
AWS deprecates the .NET 8 runtime (dotnet8) for Lambda on November 10, 2026. After that it may get no more security patches. Creating functions is blocked from July 29, 2027, and updating them from August 31, 2027.
Here are the facts we checked:
You can stay on AWS Lambda. You have to change a setting or plan before the date.
Leaving is a choice here, not a must.
Amazon Web Services is the main source for this page. AWS Lambda has not said more than what is listed here. If a fact is not on this page, we do not know it yet.
Functions on .NET 8: May get no security patches after November 10, 2026; no updates from August 31, 2027.
The date to remember is November 10, 2026. Make the change before then.
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People on Lambda functions on .NET 8 can stay if they make the change. Some would rather leave. Get the playbook for this change, and list your product here.
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