Unable to run TLS-based Undertow proxy in Java 15

I have found that my Undertow-based proxy doesn't work for TLS-based connections after I have updated to Java 15 - every request now throws an exception. In Java 13 this worked fine. Non-TLS connections works fine also in Java 15.

Java version from https://bell-sw.com/ .

openjdk version "15" 2020-09-15
OpenJDK Runtime Environment (build 15+36)
OpenJDK 64-Bit Server VM (build 15+36, mixed mode, sharing)

Error message:

[XNIO-2 I/O-2] ERROR org.xnio.listener - XNIO001007: A channel event listener threw an exception[XNIO-2 I/O-2] ERROR org.xnio.listener - XNIO001007: A channel event listener threw an exceptionjava.lang.UnsupportedOperationException: This method is deprecated and marked for removal. Use the getPeerCertificates() method instead. at java.base/javax.net.ssl.SSLSession.getPeerCertificateChain(SSLSession.java:295) at io.undertow.server.protocol.http2.Http2SslSessionInfo.getPeerCertificateChain(Http2SslSessionInfo.java:76) at io.undertow.server.handlers.proxy.ProxyHandler$ProxyAction.run(ProxyHandler.java:551) at io.undertow.util.SameThreadExecutor.execute(SameThreadExecutor.java:35) at io.undertow.server.HttpServerExchange.dispatch(HttpServerExchange.java:826) at io.undertow.server.handlers.proxy.ProxyHandler$ProxyClientHandler.completed(ProxyHandler.java:335) at io.undertow.server.handlers.proxy.ProxyHandler$ProxyClientHandler.completed(ProxyHandler.java:309) at io.undertow.server.handlers.proxy.ProxyConnectionPool.connectionReady(ProxyConnectionPool.java:353) at io.undertow.server.handlers.proxy.ProxyConnectionPool.access$900(ProxyConnectionPool.java:61) at io.undertow.server.handlers.proxy.ProxyConnectionPool$2.completed(ProxyConnectionPool.java:287) at io.undertow.server.handlers.proxy.ProxyConnectionPool$2.completed(ProxyConnectionPool.java:274) at io.undertow.client.http2.Http2ClientProvider$4.handleEvent(Http2ClientProvider.java:138) at io.undertow.client.http2.Http2ClientProvider$4.handleEvent(Http2ClientProvider.java:135) at io.undertow.client.ALPNClientSelector$2.handleSelected(ALPNClientSelector.java:125) at io.undertow.client.ALPNClientSelector$2.handleEvent(ALPNClientSelector.java:83) at io.undertow.client.ALPNClientSelector$2.handleEvent(ALPNClientSelector.java:77) at org.xnio.ChannelListeners.invokeChannelListener(ChannelListeners.java:92) at org.xnio.conduits.ReadReadyHandler$ChannelListenerHandler.readReady(ReadReadyHandler.java:66) at io.undertow.protocols.ssl.SslConduit$SslReadReadyHandler.readReady(SslConduit.java:1211) at io.undertow.protocols.ssl.SslConduit$1.run(SslConduit.java:180) at org.xnio.nio.WorkerThread.safeRun(WorkerThread.java:612) at org.xnio.nio.WorkerThread.run(WorkerThread.java:479)