We just released diaspora* version 0.5.9.1 which updates Nokogiri to 1.6.8, which in turn updates libxml2 to 2.9.4 and libxslt to 1.1.29, addressing a range of security issues. See the announcement on ruby-security-ann for more details.

Updating

Please update as soon as possible. Update instructions are available as usual in the wiki.