So, I found it interesting the "response" I got from exchanges when reporting the Pharma Exploit. TL;DR; some malicious miners could mine blocks significantly faster than legitimate miners.
In all, 3 coins and 3 altcoin exchanges were affected. The coins being Pharma (2 exchanges), MasterDoge, and Hexxcoin (1 exchange). The 3 exchanges are C-CEX, BlueTrade, and Yobit. I also sent a message to Bittrex because I thought a coin was affected that they had a market for, but that was a mistake and the coin was not actually affected.
Responses from exchanges:
- C-CEX: No response, market still online
- Yobit: No response, market still online
- BlueTrade: Response summarized as "this exploit only affects the miners and because it doesn't affect transaction balances, we will keep the market up." (which is bullshit), market still online
- Bittrex: Response within 30 minutes asking for more details (at this point I indicated it doesn't actually affect a coin I thought it did), unaffected
So, there you go. Four exchanges contacted about a security problem. One replied back that was actually concerned about it.