GHSA-PHWJ-RPRQ-35PP
Vulnerability from github – Published: 2026-06-19 16:37 – Updated: 2026-06-19 16:37Summary
Nokogiri’s CRuby native extension could leave a Ruby wrapper pointing to freed memory when replacing the value of an XML attribute. If Ruby code had already accessed an attribute child node, Nokogiri::XML::Attr#value= could free the underlying native child node while the wrapper remained reachable through the document node cache. A later use of the freed child node or a Ruby GC mark could dereference an invalid pointer, causing an invalid read and a possible segfault.
Nokogiri 1.19.4 preserves any already-wrapped attribute child nodes before replacing the attribute value.
JRuby is not affected.
Severity
The Nokogiri maintainers have evaluated this as low severity. Reaching it requires an unusual API-usage pattern that does not arise during normal use. The application must directly access an attribute's child node and then replace that same attribute's value via Attr#value= or #content=. Nokogiri 1.19.4 makes this pattern safe with no change to the public API. Already-wrapped attribute child nodes are preserved before the value is replaced.
Mitigation
Upgrade to Nokogiri 1.19.4 or later.
As a workaround, avoid accessing attribute child nodes directly via Attr#child or similar before mutating the same attribute’s value.
Credit
This issue was responsibly reported by Zheng Yu from depthfirst.com.
{
"affected": [
{
"package": {
"ecosystem": "RubyGems",
"name": "nokogiri"
},
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"fixed": "1.19.4"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [],
"database_specific": {
"cwe_ids": [
"CWE-416",
"CWE-825"
],
"github_reviewed": true,
"github_reviewed_at": "2026-06-19T16:37:46Z",
"nvd_published_at": null,
"severity": "LOW"
},
"details": "### Summary\n\nNokogiri\u2019s CRuby native extension could leave a Ruby wrapper pointing to freed memory when replacing the value of an XML attribute. If Ruby code had already accessed an attribute child node, `Nokogiri::XML::Attr#value=` could free the underlying native child node while the wrapper remained reachable through the document node cache. A later use of the freed child node or a Ruby GC mark could dereference an invalid pointer, causing an invalid read and a possible segfault.\n\nNokogiri 1.19.4 preserves any already-wrapped attribute child nodes before replacing the attribute value.\n\nJRuby is not affected.\n\n### Severity\n\nThe Nokogiri maintainers have evaluated this as low severity. Reaching it requires an unusual API-usage pattern that does not arise during normal use. The application must directly access an attribute\u0027s child node and then replace that same attribute\u0027s value via `Attr#value=` or `#content=`. Nokogiri 1.19.4 makes this pattern safe with no change to the public API. Already-wrapped attribute child nodes are preserved before the value is replaced.\n\n### Mitigation\n\nUpgrade to Nokogiri 1.19.4 or later.\n\nAs a workaround, avoid accessing attribute child nodes directly via `Attr#child` or similar before mutating the same attribute\u2019s value.\n\n### Credit\n\nThis issue was responsibly reported by Zheng Yu from depthfirst.com.",
"id": "GHSA-phwj-rprq-35pp",
"modified": "2026-06-19T16:37:46Z",
"published": "2026-06-19T16:37:46Z",
"references": [
{
"type": "WEB",
"url": "https://github.com/sparklemotion/nokogiri/security/advisories/GHSA-phwj-rprq-35pp"
},
{
"type": "PACKAGE",
"url": "https://github.com/sparklemotion/nokogiri"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "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",
"type": "CVSS_V4"
}
],
"summary": "Nokogiri: Possible Use-After-Free when setting an attribute value via `Nokogiri::XML::Attr#value=` or `#content=`"
}
Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
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- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.
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