- < 1.6.0
- >= 1.6.8
Nokogiri is affected by series of vulnerabilities in libxml2 and libxslt, which are libraries Nokogiri depends on. It was discovered that libxml2 and libxslt incorrectly handled certain malformed documents, which can allow malicious users to cause issues ranging from denial of service to remote code execution attacks.
For more information, the Ubuntu Security Notice is a good start: http://www.ubuntu.com/usn/usn-2994-1/