Tor 0.2.6.7 is a very important update, as it fixes two security issues that could be used by an attacker to either crash hidden services or clients visiting the respective hidden services. As such, an issue that could cause halting of a hidden service by triggering an assertion failure via a malicious client has been fixed, as well as a bug that could caused a client to crash with an assertion failure if a malformed hidden service descriptor was parsed.