GHSA-353f-x4gh-cqq8: Nokogiri Nokogiri Patches Vendored Libxml2 To Vulnerability

CRITICAL
Published
Advisory Summary

GHSA-353f-x4gh-cqq8 is a CRITICAL nokogiri patches vendored libxml2 to vulnerability (General Security Weakness) affecting Nokogiri libraries in the RubyGems ecosystem. The issue involves nokogiri patches vendored libxml2 to resolve multiple cves. Remediation is available by upgrading affected packages to version 1.18.9.

GHSA-353f-x4gh-cqq8 at a Glance

CVE Identifier N/A
GHSA Identifier GHSA-353f-x4gh-cqq8
Severity CRITICAL
CVSS v3.1 Base Score N/A
CWE Classification General Security Weakness
Affected Product Nokogiri
Package Ecosystem RubyGems
Published Date
Last Updated

How to Fix GHSA-353f-x4gh-cqq8

To remediate this vulnerability, upgrade all affected Nokogiri dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

nokogiri fixed: 1.18.9
Upgrade nokogiri to 1.18.9
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release:

inspect dependencies for nokogiri

How to Check if You Are Affected

To determine whether your application is affected by GHSA-353f-x4gh-cqq8, inspect your project dependencies for Nokogiri:

inspect dependencies for nokogiri

Analyze the terminal output to locate any version of Nokogiri in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 1.18.9), your application is affected.

Note: Verify declared build manifests and deployed runtime container environments.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under General Security Weakness. In Nokogiri, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

## Summary Nokogiri v1.18.9 patches the vendored libxml2 to address CVE-2025-6021, CVE-2025-6170, CVE-2025-49794, CVE-2025-49795, and CVE-2025-49796. ## Impact and severity ### CVE-2025-6021 A flaw was found in libxml2's xmlBuildQName function, where integer overflows in buffer size calculations can lead to a stack-based buffer overflow. This issue can result in memory corruption or a denial of service when processing crafted input. NVD claims a severity of 7.5 High (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H) Fixed by applying https://gitlab.gnome.org/GNOME/libxml2/-/commit/17d950ae ### CVE-2025-6170 A flaw was found in the interactive shell of the xmllint command-line tool, used for parsing XML files. When a user inputs an overly long command, the program does not check the input size properly, which can cause it to crash. This issue might allow attackers to run harmful code in rare configurations without modern protections. NVD claims a severity of 2.5 Low (CVSS:3.1/AV:L/AC:H/PR:N/UI:R/S:U/C:N/I:N/A:L) Fixed by applying https://gitlab.gnome.org/GNOME/libxml2/-/commit/5e9ec5c1 ### CVE-2025-49794 A use-after-free vulnerability was found in libxml2. This issue occurs when parsing XPath elements under certain circumstances when the XML schematron has the <sch:name path="..."/> schema elements. This flaw allows a malicious actor to craft a malicious XML document used as input for libxml, resulting in the program's crash using libxml or other possible undefined behaviors. NVD claims a severity of 9.1 Critical (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H) Fixed by applying https://gitlab.gnome.org/GNOME/libxml2/-/commit/81cef8c5 ### CVE-2025-49795 A NULL pointer dereference vulnerability was found in libxml2 when processing XPath XML expressions. This flaw allows an attacker to craft a malicious XML input to libxml2, leading to a denial of service. NVD claims a severity of 7.5 High (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H) Fixed by applying https://gitlab.gnome.org/GNOME/libxml2/-/commit/62048278 ### CVE-2025-49796 A vulnerability was found in libxml2. Processing certain sch:name elements from the input XML file can trigger a memory corruption issue. This flaw allows an attacker to craft a malicious XML input file that can lead libxml to crash, resulting in a denial of service or other possible undefined behavior due to sensitive data being corrupted in memory. NVD claims a severity of 9.1 Critical (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H) Fixed by applying https://gitlab.gnome.org/GNOME/libxml2/-/commit/81cef8c5 ## Affected Versions - Nokogiri < 1.18.9 when using CRuby (MRI) with vendored libxml2 ## Patched Versions - Nokogiri >= 1.18.9 ## Mitigation Upgrade to Nokogiri v1.18.9 or later. Users who are unable to upgrade Nokogiri may also choose a more complicated mitigation: compile and link Nokogiri against patched external libxml2 libraries which will also address these same issues. ## References - https://github.com/sparklemotion/nokogiri/pull/3526 - https://nvd.nist.gov/vuln/detail/CVE-2025-6021 - https://nvd.nist.gov/vuln/detail/CVE-2025-6170 - https://nvd.nist.gov/vuln/detail/CVE-2025-49794 - https://nvd.nist.gov/vuln/detail/CVE-2025-49795 - https://nvd.nist.gov/vuln/detail/CVE-2025-49796

GHSA-353f-x4gh-cqq8 Affected Nokogiri Versions

1 component(s)
Fixed Versions:
1.18.9
Product / Package Ecosystem Affected Versions Fixed Version
nokogiri
RubyGems
< 1.18.9
1.18.9

References

Frequently Asked Questions

What is GHSA-353f-x4gh-cqq8?
GHSA-353f-x4gh-cqq8 is a security vulnerability in Nokogiri involving Nokogiri patches vendored libxml2 to resolve multiple CVEs under General Security Weakness.
Which Nokogiri versions are affected?
Affected versions include releases prior to 1.18.9 across affected packages: nokogiri.
What version fixes GHSA-353f-x4gh-cqq8?
Upgrading to 1.18.9 (or the latest patched release for your respective branch) resolves the vulnerability.
Is nokogiri affected?
Yes, nokogiri is affected in releases prior to 1.18.9. Upgrade your dependency to 1.18.9 or later.
What CWE is associated with GHSA-353f-x4gh-cqq8?
GHSA-353f-x4gh-cqq8 is classified under General Security Weakness.
How can I check RubyGems dependencies for GHSA-353f-x4gh-cqq8?
Run the dependency tree command: 'inspect dependencies for nokogiri'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-353f-x4gh-cqq8",
  "modified" : "2025-07-21T19:35:18Z",
  "published" : "2025-07-21T19:35:18Z",
  "aliases" : [ ],
  "summary" : "Nokogiri patches vendored libxml2 to resolve multiple CVEs",
  "details" : "## Summary\n\nNokogiri v1.18.9 patches the vendored libxml2 to address CVE-2025-6021, CVE-2025-6170, CVE-2025-49794, CVE-2025-49795, and CVE-2025-49796.\n\n## Impact and severity\n\n### CVE-2025-6021\n\nA flaw was found in libxml2's xmlBuildQName function, where integer overflows in buffer size calculations can lead to a stack-based buffer overflow. This issue can result in memory corruption or a denial of service when processing crafted input.\n\nNVD claims a severity of 7.5 High (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H)\n\nFixed by applying https://gitlab.gnome.org/GNOME/libxml2/-/commit/17d950ae\n\n### CVE-2025-6170\n\nA flaw was found in the interactive shell of the xmllint command-line tool, used for parsing XML files. When a user inputs an overly long command, the program does not check the input size properly, which can cause it to crash. This issue might allow attackers to run harmful code in rare configurations without modern protections.\n\nNVD claims a severity of 2.5 Low (CVSS:3.1/AV:L/AC:H/PR:N/UI:R/S:U/C:N/I:N/A:L)\n\nFixed by applying https://gitlab.gnome.org/GNOME/libxml2/-/commit/5e9ec5c1\n\n### CVE-2025-49794\n\nA use-after-free vulnerability was found in libxml2. This issue occurs when parsing XPath elements under certain circumstances when the XML schematron has the <sch:name path=\"...\"/> schema elements. This flaw allows a malicious actor to craft a malicious XML document used as input for libxml, resulting in the program's crash using libxml or other possible undefined behaviors.\n\nNVD claims a severity of 9.1 Critical (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H)\n\nFixed by applying https://gitlab.gnome.org/GNOME/libxml2/-/commit/81cef8c5\n\n### CVE-2025-49795\n\nA NULL pointer dereference vulnerability was found in libxml2 when processing XPath XML expressions. This flaw allows an attacker to craft a malicious XML input to libxml2, leading to a denial of service.\n\nNVD claims a severity of 7.5 High (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H)\n\nFixed by applying https://gitlab.gnome.org/GNOME/libxml2/-/commit/62048278\n\n### CVE-2025-49796\n\nA vulnerability was found in libxml2. Processing certain sch:name elements from the input XML file can trigger a memory corruption issue. This flaw allows an attacker to craft a malicious XML input file that can lead libxml to crash, resulting in a denial of service or other possible undefined behavior due to sensitive data being corrupted in memory.\n\nNVD claims a severity of 9.1 Critical (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H)\n\nFixed by applying https://gitlab.gnome.org/GNOME/libxml2/-/commit/81cef8c5\n\n## Affected Versions\n\n- Nokogiri < 1.18.9 when using CRuby (MRI) with vendored libxml2\n\n## Patched Versions\n\n- Nokogiri >= 1.18.9\n\n## Mitigation\n\nUpgrade to Nokogiri v1.18.9 or later.\n\nUsers who are unable to upgrade Nokogiri may also choose a more complicated mitigation: compile and link Nokogiri against patched external libxml2 libraries which will also address these same issues.\n\n## References\n\n- https://github.com/sparklemotion/nokogiri/pull/3526\n- https://nvd.nist.gov/vuln/detail/CVE-2025-6021\n- https://nvd.nist.gov/vuln/detail/CVE-2025-6170\n- https://nvd.nist.gov/vuln/detail/CVE-2025-49794\n- https://nvd.nist.gov/vuln/detail/CVE-2025-49795\n- https://nvd.nist.gov/vuln/detail/CVE-2025-49796",
  "severity" : [ ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "RubyGems",
      "name" : "nokogiri"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "1.18.9"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/sparklemotion/nokogiri/security/advisories/GHSA-353f-x4gh-cqq8"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2025-49794"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2025-49795"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2025-49796"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2025-6021"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2025-6170"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/sparklemotion/nokogiri/pull/3526"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/sparklemotion/nokogiri"
  } ],
  "database_specific" : {
    "cwe_ids" : [ ],
    "severity" : "CRITICAL",
    "github_reviewed" : true,
    "github_reviewed_at" : "2025-07-21T19:35:18Z",
    "nvd_published_at" : null
  }
}