GHSA-5PRR-V3J2-97MH
Vulnerability from github – Published: 2026-06-19 16:36 – Updated: 2026-06-19 16:36Summary
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.
Nokogiri 1.19.4 performs the bounds check against the full-width index.
Severity
The Nokogiri maintainers have evaluated this as medium severity.
Exploitation requires an application to pass an attacker-controlled integer to NodeSet#[]. The primary impact is a controlled crash (denial of service), with potential for memory disclosure on CRuby.
On JRuby, Nokogiri is not affected by this vulnerability.
Mitigation
Upgrade to Nokogiri 1.19.4 or later.
As a workaround, applications that index a NodeSet with externally-supplied integers can validate the index against node_set.length before use, or avoid passing untrusted values as an index.
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-125",
"CWE-190"
],
"github_reviewed": true,
"github_reviewed_at": "2026-06-19T16:36:42Z",
"nvd_published_at": null,
"severity": "MODERATE"
},
"details": "### Summary\n\n`Nokogiri::XML::NodeSet#[]` (and its alias `#slice`) checked the requested index against the node set\u0027s 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\u0027s 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.\n\nNokogiri 1.19.4 performs the bounds check against the full-width index.\n\n### Severity\n\nThe Nokogiri maintainers have evaluated this as medium severity.\n\nExploitation requires an application to pass an attacker-controlled integer to `NodeSet#[]`. The primary impact is a controlled crash (denial of service), with potential for memory disclosure on CRuby.\n\nOn JRuby, Nokogiri is not affected by this vulnerability.\n\n### Mitigation\n\nUpgrade to Nokogiri 1.19.4 or later.\n\nAs a workaround, applications that index a `NodeSet` with externally-supplied integers can validate the index against `node_set.length` before use, or avoid passing untrusted values as an index.\n\n### Credit\n\nThis issue was responsibly reported by Zheng Yu from depthfirst.com.",
"id": "GHSA-5prr-v3j2-97mh",
"modified": "2026-06-19T16:36:42Z",
"published": "2026-06-19T16:36:42Z",
"references": [
{
"type": "WEB",
"url": "https://github.com/sparklemotion/nokogiri/security/advisories/GHSA-5prr-v3j2-97mh"
},
{
"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:L/VI:N/VA:L/SC:N/SI:N/SA:N",
"type": "CVSS_V4"
}
],
"summary": "Nokogiri: Possible Out-of-Bounds Read in `Nokogiri::XML::NodeSet#[]`"
}
Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
- Confirmed: The vulnerability has been validated from an analyst's perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
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- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
- 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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