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 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.
- Products
- Not specified
- Affected versions
- Not specified
- Fixed versions
- Not specified
- CVEs
- CVE-2026-57236
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 4 Nov 2026, 13:23 UTC · Revision 1
Source evidence
Nokogiri: Possible Use-After-Free when `Nokogiri::XML::Document#encoding=` raises an exception
core-osv · Original sourcePublished 25 Jun 2026, 14:29 UTC
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.
osv:CVE-2026-57236
Complete source record
{
"id": "036962db381cc481417c0843ff77b2c0095746a7bb35be1bef005cc97a5971b0",
"url": "https://osv.dev/vulnerability/CVE-2026-57236",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "Nokogiri: Possible Use-After-Free when `Nokogiri::XML::Document#encoding=` raises an exception",
"summary": "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.",
"evidence": "osv:CVE-2026-57236",
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"database_specific": {
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],
"modified": "2026-10-28T02:30:35.670155163Z",
"provider": "osv",
"references": [
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"https://github.com/sparklemotion/nokogiri/security/advisories/GHSA-5v8h-3h3q-446p",
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"source_id": "core-osv",
"document_id": 503042,
"published_at": "2026-06-25T14:29:14.181+00:00"
}