Nokogiri is a Rubygem providing HTML, XML, SAX, and Reader parsers with XPath and CSS selector support. In Nokogiri v1.12.4 and earlier, on JRuby only, the SAX parser resolves external entities by default. Users of Nokogiri on JRuby who parse untrusted documents using any of these classes are affected: Nokogiri::XML::SAX::Parse, Nokogiri::HTML4::SAX::Parser or its alias Nokogiri::HTML::SAX::Parser, Nokogiri::XML::SAX::PushParser, and Nokogiri::HTML4::SAX::PushParser or its alias Nokogiri::HTML::SAX::PushParser. JRuby users should upgrade to Nokogiri v1.12.5 or later to receive a patch for this issue. There are no workarounds available for v1.12.4 or earlier. CRuby users are not affected.

The Unity Linux 20 host has a package installed that is affected by a vulnerability as referenced in the UTSA-2026-016636 advisory.

    Nokogiri is a Rubygem providing HTML, XML, SAX, and Reader parsers with XPath and CSS selector support. In     Nokogiri v1.12.4 and earlier, on JRuby only, the SAX parser resolves external entities by default. Users     of Nokogiri on JRuby who parse untrusted documents using any of these classes are affected:
    Nokogiri::XML::SAX::Parse, Nokogiri::HTML4::SAX::Parser or its alias Nokogiri::HTML::SAX::Parser,     Nokogiri::XML::SAX::PushParser, and Nokogiri::HTML4::SAX::PushParser or its alias     Nokogiri::HTML::SAX::PushParser. JRuby users should upgrade to Nokogiri v1.12.5 or later to receive a     patch for this issue. There are no workarounds available for v1.12.4 or earlier. CRuby users are not     affected.

Tenable has extracted the preceding description block directly from the Unity Linux security advisory.

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

An update of the rubygem package has been released.

An update of the rubygem package has been released.

  - A command injection vulnerability in Nokogiri v1.10.3 and earlier allows commands to be executed in a     subprocess via Ruby's `Kernel.open` method. Processes are vulnerable only if the undocumented method     `Nokogiri::CSS::Tokenizer#load_file` is being called with unsafe user input as the filename. This     vulnerability appears in code generated by the Rexical gem versions v1.0.6 and earlier. Rexical is used by     Nokogiri to generate lexical scanner code for parsing CSS queries. The underlying vulnerability was     addressed in Rexical v1.0.7 and Nokogiri upgraded to this version of Rexical in Nokogiri v1.10.4.
    (CVE-2019-5477)

  - Nokogiri is a Rubygem providing HTML, XML, SAX, and Reader parsers with XPath and CSS selector support. In     Nokogiri before version 1.11.0.rc4 there is an XXE vulnerability. XML Schemas parsed by     Nokogiri::XML::Schema are trusted by default, allowing external resources to be accessed over the network,     potentially enabling XXE or SSRF attacks. This behavior is counter to the security policy followed by     Nokogiri maintainers, which is to treat all input as untrusted by default whenever possible. This is fixed     in Nokogiri version 1.11.0.rc4. (CVE-2020-26247)

  - Nokogiri is a Rubygem providing HTML, XML, SAX, and Reader parsers with XPath and CSS selector support. In     Nokogiri v1.12.4 and earlier, on JRuby only, the SAX parser resolves external entities by default. Users     of Nokogiri on JRuby who parse untrusted documents using any of these classes are affected:
    Nokogiri::XML::SAX::Parse, Nokogiri::HTML4::SAX::Parser or its alias Nokogiri::HTML::SAX::Parser,     Nokogiri::XML::SAX::PushParser, and Nokogiri::HTML4::SAX::PushParser or its alias     Nokogiri::HTML::SAX::PushParser. JRuby users should upgrade to Nokogiri v1.12.5 or later to receive a     patch for this issue. There are no workarounds available for v1.12.4 or earlier. CRuby users are not     affected. (CVE-2021-41098)

ID	Name	Product	Family	Severity
316236	Unity Linux 20.1060e / 20.1070e Security Update: rubygem-nokogiri (UTSA-2026-016636)	Nessus	Unity Linux Local Security Checks	high
203157	Photon OS 4.0: Rubygem PHSA-2021-4.0-0115	Nessus	PhotonOS Local Security Checks	high
155347	Photon OS 2.0: Rubygem PHSA-2021-2.0-0413	Nessus	PhotonOS Local Security Checks	critical

Detections

Analytics

CVE-2021-41098

high

Tenable Plugins

high

high

critical