Posting about such things on this forum is not going to be helpful at all; very few of the Core developers actually visit this forum. Additionally posts like these are usually ignored as they typically have no substance and only serve to fuel public hysteria and FUD. If you believe that you have found a critical security issue, send an email to
security@bitcoincore.org. If you are concerned about the privacy of the email, then encrypt your message with some of the PGP keys found here:
https://github.com/bitcoin/bitcoin/tree/master/contrib/gitian-keys (you probably want to encrypt to at least laanwj, gmaxwell, jonasschnelli, luke-jr, bluematt, and sipa)