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.
https://github.com/sparklemotion/nokogiri/security/advisories/GHSA-qv4q-mr5r-qprj
https://github.com/sparklemotion/nokogiri/commit/9fe0761c47c0d4270d1a5220cfd25de080350d50
https://github.com/sparklemotion/nokogiri/commit/85410e38410f670cbbc8c5b00d07b843caee88ce