trac -- reStructuredText breach of privacy and denial of service vulnerability

The Trac 0.9.6 Release Notes reports:

Fixed reStructuredText breach of privacy and denial of
service vulnerability found by Felix Wiemann.
The discovered vulnerability requires docutils to be
installed and enabled. Systems that do not have docutils
installed or enabled are not vulnerable. As of this
version version 0.3.9 or greater of docutils is required
for using reStructuredText markup in Trac.