CVE-2026-57234 Nokogiri: XML::Schema on JRuby allows network requests when NONET is set, bypassing CVE-2020-26247

What is CVE-2026-57234?

CVE-2026-57234 is a low-severity vulnerability in sparklemotion nokogiri, published on 25 Jun 2026. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.

Official description

Nokogiri is an open source XML and HTML library for the Ruby programming language. Prior to 1.19.4, the NONET parse option, which Nokogiri turns on by default for Nokogiri::XML::Schema (see CVE-2020-26247), was not correctly enforced on the JRuby implementation. As a result, a schema parsed with default options could still cause external resources to be fetched over the network, potentially enabling SSRF or XXE attacks. This vulnerability is fixed in 1.19.4.

Weakness: CWE-611, CWE-184, CWE-178

Which versions are affected by CVE-2026-57234?

2 open source packages ship an affected version, including nokogiri. It affects 1 product.

Products include Nokogiri Nokogiri.

How do I fix CVE-2026-57234?

Upgrade nokogiri to 1.19.4 or later.

Is CVE-2026-57234 being exploited?

There is no known exploitation of CVE-2026-57234 in the wild and no public exploit code.

Other vulnerabilities in sparklemotion nokogiri

• CVE-2026-79770 Nokogiri before 1.19.3 ReDoS via CSS selector tokenizer High 8.7
• CVE-2022-23476 Unchecked return value from xmlTextReaderExpand in Nokogiri High 7.5
• CVE-2021-41098 Improper Restriction of XML External Entity Reference (XXE) in Nokogiri on JRuby High 7.5
• CVE-2012-6685 Nokogiri is vulnerable to XML External Entity (XXE) attack High 7.5
• CVE-2026-79771 Nokogiri before 1.19.3 Memory Leak via XSLT Transform Medium 6.9

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as AZL-91080, BELL-CVE-2026-57234, CLEANSTART-2026-EA82702, DEBIAN-CVE-2026-57234, GHSA-8678-w3jw-xfc2, MINI-7hcq-phpp-7mg8 and 8 more.