Tor 0.2.5.12 and 0.6.7 fixes two security issues that could be used by an attacker to crash hidden services, or crash clients visiting hidden services. Hidden services should upgrade as soon as possible; clients should upgrade whenever packages become available. These releases also contain two simple improvements to make hidden services a bit less vulnerable to denial-of-service attacks. Tor Browser team evaluating whether to put out a new Tor Browser stable release with these fixes, or wait until next week for their scheduled next stable release.”]
Source: https://blog.torproject.org/tor-02512-and-0267-are-released