I'm honestly not sure. I haven't been able to read the original report (which is not in English). My guess is that it did not receive direct attention.

I note that Cap'n Proto did receive some scrutiny from security guru (and personal friend) Ben Laurie in the past:

https://capnproto.org/news/2015-03-02-security-advisory-and-...

My next job is at a company that is a heavy user of Cap'n Proto, so expect more progress on this front going forward.