CVE-2026-57235: Nokogiri

High severity, CVSS 8.2. EPSS: 0.4% chance of exploitation in the next 30 days.

Nokogiri is an open source XML and HTML library for the Ruby programming language. Prior to 1.19.4, Nokogiri::XML::NodeSet#[] (and its alias #slice) checked the requested index against the node set's bounds using a 32-bit-truncated copy of the index. A large negative index could pass the check and then be used at full width, reading outside the node set's storage. On CRuby this is an out-of-bounds read that typically crashes the process; on JRuby it is not memory-unsafe but returns an incorrect node. This vulnerability is fixed in 1.19.4.

Affected products

• Nokogiri Nokogiri: before 1.19.4 (fixed in 1.19.4)

Published 2026-06-25. Last modified 2026-06-26.