Android default HttpClientHandler and Chain validation failed #10594
Description
Description
Starting from November 11th, 2025, our Android application is no longer able to reach an Azure Web App when using the default HttpClient handler. The request immediately fails with an exception thrown during the HTTP/TLS handshake.
When replacing the default platform handler with SocketsHttpHandler, all requests work again as expected, with no code changes other than the handler substitution.
This suggests a possible compatibility issue between the Android default handler and recent changes in Azure Web App TLS/HTTP configuration, while SocketsHttpHandler continues to function correctly.
Expected behavior:
HttpClient using the default Android handler should continue to work as before and be able to connect to Azure Web Apps.
Actual behavior:
Using the default handler results in a runtime exception and the request never reaches the server. Using SocketsHttpHandler makes the same request succeed.
Environment:
.NET MAUI version: 9
Android version / device model: More than one
Steps to Reproduce
No response
Link to public reproduction project repository
No response
Version with bug
9.0.100 SR10
Is this a regression from previous behavior?
No, this is something new
Last version that worked well
No response
Affected platforms
Android
Affected platform versions
No response
Did you find any workaround?
When replacing the default platform handler with SocketsHttpHandler, all requests work again as expected, with no code changes other than the handler substitution.
Relevant log output
System.Net.Http.HttpRequestException: Connection failure
---> Javax.Net.Ssl.SSLHandshakeException: Chain validation failed
---> Java.Security.Cert.CertificateException: Chain validation failed
---> Java.Security.Cert.CertPathValidatorException: Unable to determine revocation status due to network error
---> Java.IO.IOException: Parse Generalized time, unsupported precision for seconds value