System.Net.Http.Functional.Tests.SocketsHttpHandlerTest_Cookies_Http3.GetAsyncWithRedirect_SetCookieContainer_CorrectCookiesSent fails with System.Net.Http.HttpRequestException : The request was aborted

## Build Information
Build: https://dev.azure.com/dnceng-public/cbb18261-c48f-4abb-8651-8cdcb5474649/_build/results?buildId=1594675
Build error leg or test failing: System.Net.Http.Functional.Tests.SocketsHttpHandlerTest_Cookies_Http3.GetAsyncWithRedirect_SetCookieContainer_CorrectCookiesSent
Pull request: https://github.com/dotnet/runtime/pull/133649

## Error Message

**DO NOT USE JSON BELOW IF THIS IS A BUILD BREAK** otherwise build analysis will allow pull requests to merge that break the build worse. For a build break, do not use this issue form. Make a regular new issue.

Fill the error message using [step by step known issues guidance](https://github.com/dotnet/arcade/blob/main/Documentation/Build%20Analysis/KnownIssueJsonStepByStep.md).

```json
{
"ErrorMessage": " System.Net.Http.HttpRequestException : The request was aborted",
"ErrorPattern": "",
"BuildRetry": false,
"ExcludeConsoleLog": false
}
```

### Known issue validation
**Build: :mag_right:** https://dev.azure.com/dnceng-public/public/_build/results?buildId=1594675
**Error message validated:** `[ System.Net.Http.HttpRequestException : The request was aborted`]
**Result validation:** :white_check_mark: Known issue matched with the provided build.
**Validation performed at:** 9/14/2026 2:07:44 AM UTC

### Report

|Build|Repository|Test|Pull Request|
|---|---|---|---|
|[1597695](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1597695)|dotnet/runtime|[System.Net.Http.Functional.Tests.SocketsHttpHandlerTest_Cookies_Http3.GetAsyncWithRedirect_SetCookieContainer_CorrectCookiesSent](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1597695&view=ms.vss-test-web.build-test-results-tab&runId=44108684&resultId=231866)|dotnet/runtime#133946|
|[1597340](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1597340)|dotnet/runtime|[System.Net.Http.Functional.Tests.HttpClientHandlerTest_Http3.SendAsync_RequestRejected_ClientRetries](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1597340&view=ms.vss-test-web.build-test-results-tab&runId=44098798&resultId=229400)|dotnet/runtime#133940|
|[1596986](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1596986)|dotnet/runtime|[System.Net.Http.Functional.Tests.HttpClientHandlerTest_Http3.SendAsync_RequestRejected_ClientRetries](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1596986&view=ms.vss-test-web.build-test-results-tab&runId=44085924&resultId=150064)||
|[1596529](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1596529)|dotnet/runtime|[System.Net.Http.Functional.Tests.SocketsHttpHandlerTest_Cookies_Http3.GetAsyncWithRedirect_ReceiveSetCookie_CookieSent](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1596529&view=ms.vss-test-web.build-test-results-tab&runId=44073492&resultId=196610)|dotnet/runtime#133847|
|[1596309](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1596309)|dotnet/runtime|[System.Net.Http.Functional.Tests.HttpClientHandlerTest_Http3.SendAsync_RequestRejected_ClientRetries](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1596309&view=ms.vss-test-web.build-test-results-tab&runId=44068842&resultId=223264)|dotnet/runtime#133773|
|[1596321](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1596321)|dotnet/runtime|[System.Net.Http.Functional.Tests.HttpClientHandlerTest_Http3.SendAsync_RequestRejected_ClientRetries](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1596321&view=ms.vss-test-web.build-test-results-tab&runId=44069022&resultId=188955)||
|[1596210](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1596210)|dotnet/runtime|[System.Net.Http.Functional.Tests.HttpClientHandlerTest_Http3.SendAsync_RequestRejected_ClientRetries](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1596210&view=ms.vss-test-web.build-test-results-tab&runId=44067960&resultId=208265)|dotnet/runtime#133188|
|[1595880](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1595880)|dotnet/runtime|[System.Net.Http.Functional.Tests.HttpClientHandlerTest_Http3.SendAsync_RequestRejected_ClientRetries](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1595880&view=ms.vss-test-web.build-test-results-tab&runId=44060574&resultId=208004)|dotnet/runtime#133885|
|[1595672](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1595672)|dotnet/runtime|[System.Net.Http.Functional.Tests.HttpClientHandlerTest_Http3.SendAsync_RequestRejected_ClientRetries](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1595672&view=ms.vss-test-web.build-test-results-tab&runId=44056392&resultId=218035)|dotnet/runtime#131652|
|[1595611](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1595611)|dotnet/runtime|[System.Net.Http.Functional.Tests.HttpClientHandlerTest_Http3.SendAsync_RequestRejected_ClientRetries](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1595611&view=ms.vss-test-web.build-test-results-tab&runId=44055338&resultId=221219)|dotnet/runtime#133606|
|[1595554](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1595554)|dotnet/runtime|[System.Net.Http.Functional.Tests.SocketsHttpHandlerTest_Cookies_Http3.GetAsync_Redirect_CookiesArePreserved](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1595554&view=ms.vss-test-web.build-test-results-tab&runId=44053136&resultId=229576)|dotnet/runtime#131597|
|[1595518](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1595518)|dotnet/runtime|[System.Net.Http.Functional.Tests.SocketsHttpHandlerTest_Cookies_Http3.GetAsyncWithRedirect_SetCookieContainer_CorrectCookiesSent](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1595518&view=ms.vss-test-web.build-test-results-tab&runId=44052696&resultId=229522)|dotnet/runtime#133673|
|[1595428](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1595428)|dotnet/runtime|[System.Net.Http.Functional.Tests.HttpClientHandlerTest_Http3.SendAsync_RequestRejected_ClientRetries](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1595428&view=ms.vss-test-web.build-test-results-tab&runId=44049190&resultId=209093)|dotnet/runtime#133853|
|[1595348](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1595348)|dotnet/runtime|[System.Net.Http.Functional.Tests.SocketsHttpHandlerTest_Cookies_Http3.GetAsync_Redirect_CookiesArePreserved](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1595348&view=ms.vss-test-web.build-test-results-tab&runId=44048706&resultId=211125)|dotnet/runtime#129683|
|[1595259](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1595259)|dotnet/runtime|[System.Net.Http.Functional.Tests.SocketsHttpHandlerTest_Cookies_Http3.GetAsyncWithRedirect_SetCookieContainer_CorrectCookiesSent](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1595259&view=ms.vss-test-web.build-test-results-tab&runId=44042850&resultId=221762)||
|[1594919](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1594919)|dotnet/runtime|[System.Net.Http.Functional.Tests.SocketsHttpHandlerTest_Cookies_Http3.GetAsyncWithRedirect_ReceiveSetCookie_CookieSent](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1594919&view=ms.vss-test-web.build-test-results-tab&runId=44030838&resultId=200766)||
|[1594675](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1594675)|dotnet/runtime|[System.Net.Http.Functional.Tests.SocketsHttpHandlerTest_Cookies_Http3.GetAsyncWithRedirect_SetCookieContainer_CorrectCookiesSent](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1594675&view=ms.vss-test-web.build-test-results-tab&runId=44023094&resultId=218119)|dotnet/runtime#133649|
#### Summary
|24-Hour Hit Count|7-Day Hit Count|1-Month Count|
|---|---|---|
|7|17|17|

Start with build 1594675 and the named System.Net.Http.Functional.Tests.SocketsHttpHandlerTest_Cookies_Http3.GetAsyncWithRedirect_SetCookieContainer_CorrectCookiesSent test, then compare its failure with the repeated HTTP/3 failures listed in the report. Done means identifying and fixing the cause of the aborted request and confirming the affected test passes in the relevant build.

Written by the indexing model from the issue text.