Version 0.29 of the CommonMark spec has been released:
I have also released conforming versions of the reference implementations
as well as a lua binding, an enhanced lua wrapper, and a Haskell binding.
Important note: The reference implementations have changed to being “safe by default,” so that raw HTML and potentially unsafe attributes are stripped from the rendered HTML output unless you explicitly set the “unsafe” option. Authors of bindings and applications that use these libraries may need to make adjustments.
Most of the changes to the spec are fairly minor, fiddly things. One more significant change concerns code spans: interior spaces are no longer collapsed, and leading and trailing space is only removed if there are both leading and trailing spaces, and if the code span is not composed entirely of spaces.