CVE-2026-57236 — Nokogiri: Possible Use-After-Free when `Nokogiri::XML::Document#encoding=` raises an exception
Nokogiri is an open source XML and HTML library for the Ruby programming language. Prior to 1.19.4, calling Document#encoding= with an invalid encoding (e.g., a non-string, or a…
Published: 2026-06-25 · CVSS: 1.7 · CVSS 4.0
Nokogiri is an open source XML and HTML library for the Ruby programming language. Prior to 1.19.4, calling Document#encoding= with an invalid encoding (e.g., a non-string, or a string containing a null byte) raises an exception, but only after freeing the document's current encoding string without replacing it. The document is left referencing freed memory, so the next call to Document#encoding reads invalid memory, which can cause a segfault or leak freed bytes into a Ruby String. Affects the CRuby (libxml2) implementation only; JRuby is not affected. This vulnerability is fixed in 1.19.4.
Source: CVE Program · Revision 8b16575c39f1e1810c5e863010da073d2d3285e7