GHSA-5PRR-V3J2-97MH

Vulnerability from github – Published: 2026-06-19 16:36 – Updated: 2026-06-19 16:36
VLAI
Summary
Nokogiri: Possible Out-of-Bounds Read in `Nokogiri::XML::NodeSet#[]`
Details

Summary

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.

Severity
6.3 (Medium)
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
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{
  "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#[]`"
}


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Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

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  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
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