Nokogiri: Possible Use-After-Free when `Nokogiri::XML::Document#encoding=` raises an exception_CVE-2026-57236

1.7 / 10

LOW

CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:U

Description

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.

Basic Information

ID CVE-2026-57236

Source GitHub_M

Published Jun 25, 2026 at 14:29

Modified Jun 25, 2026 at 15:32

Affected Product

Vendor sparklemotion

Product nokogiri

Version < 1.19.4

Affected Versions sparklemotion nokogiri < 1.19.4

CWE Classification

CWE-416

References

github.com /sparklemotion/nokogiri/security/advisories/GHSA-5v8h-3h3q-446p

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