CVE-2022-23476: Unchecked Return Value

Nokogiri is an open source XML and HTML library for the Ruby programming language. Nokogiri 1.13.8 and 1.13.9 fail to check the return value from xmlTextReaderExpand in the method Nokogiri::XML::Reader#attribute_hash. This can lead to a null pointer exception when invalid markup is being parsed. For applications using XML::Reader to parse untrusted inputs, this may potentially be a vector for a denial of service attack. Users are advised to upgrade to Nokogiri >= 1.13.10. Users may be able to search their code for calls to either XML::Reader#attributes or XML::Reader#attribute_hash to determine if they are affected.