### Navigation - [index](# "General Index") - [modules](# "Python Module Index") | - [next](# "What鈥檚 new in Tornado 3.2") | - [previous](# "What鈥檚 new in Tornado 3.2.2") | - [Tornado 4.4.dev1 documentation](#) » - [Release notes](#) » # What's new in Tornado 3.2.1 ### May 5, 2014 ### Security fixes - The signed-value format used by [`RequestHandler.set_secure_cookie`](# "tornado.web.RequestHandler.set_secure_cookie")and [`RequestHandler.get_secure_cookie`](# "tornado.web.RequestHandler.get_secure_cookie") has changed to be more secure.**This is a disruptive change**. The `secure_cookie` functionstake new `version` parameters to support transitions between cookieformats. - The new cookie format fixes a vulnerability that may be present inapplications that use multiple cookies where the name of one cookieis a prefix of the name of another. - To minimize disruption, cookies in the older format will be acceptedby default until they expire. Applications that may be vulnerablecan reject all cookies in the older format by passing `min_version=2`to [`RequestHandler.get_secure_cookie`](# "tornado.web.RequestHandler.get_secure_cookie"). - Thanks to Joost Pol of [Certified Secure](https://www.certifiedsecure.com) [https://www.certifiedsecure.com]for reporting this issue. ### Backwards-compatibility notes - Signed cookies issued by [`RequestHandler.set_secure_cookie`](# "tornado.web.RequestHandler.set_secure_cookie") in Tornado3.2.1 cannot be read by older releases. If you need to run 3.2.1in parallel with older releases, you can pass `version=1` to[`RequestHandler.set_secure_cookie`](# "tornado.web.RequestHandler.set_secure_cookie") to issue cookies that arebackwards-compatible (but have a known weakness, so this optionshould only be used for a transitional period). ### Other changes - The C extension used to speed up the websocket module now compilescorrectly on Windows with MSVC and 64-bit mode. The fallback tothe pure-Python alternative now works correctly on Mac OS X machineswith no C compiler installed. © Copyright 2009-2016, The Tornado Authors. Created using [Sphinx](http://sphinx-doc.org/) 1.3.5.