Spring Security - How to handle a RuntimeException in a custom AuthenticationFilter?

Using Spring Security, I have created a custom UsernamePasswordAuthenticationFilter. In this filter's attemptAuthentication method, I would like to retrieve the body of the HttpServletRequest, since credentials should be passed inside the body instead of request parameters.

I think I have found a good way to achieve this, but I am unsure about how to handle the IOException that could now occur inside this method. I have to catch the IOException inside this method, since the original method, which I override, does not throw an IOException.

This is my implementation:

@RequiredArgsConstructor
public class AuthenticationFilter extends UsernamePasswordAuthenticationFilter {

  private final AuthenticationManager authenticationManager;

  @Override
  public Authentication attemptAuthentication(HttpServletRequest request, HttpServletResponse response)
    throws AuthenticationException {
    try {
      UserDTO user = new ObjectMapper().readValue(request.getInputStream(), UserDTO.class);
      UsernamePasswordAuthenticationToken authenticationToken =
        new UsernamePasswordAuthenticationToken(user.getUsername(), user.getPassword());
      return authenticationManager.authenticate(authenticationToken);
    } catch (IOException e) {
      throw new RuntimeException(e);
    }
  }

My IDE suggests to throw a custom exception instead of a RuntimeException. But since this filter is part of the Spring Security filter chain, I am unsure about what should happen in case of an IOException.