GHSA-5jhf-fpp7-v2pv: Duplicate Advisory Nokogiri CSS Selector Tokenizer Has Vulnerability

HIGH
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CVSS 7.5
CWE-1333
Published
Advisory Summary

GHSA-5jhf-fpp7-v2pv is a HIGH (CVSS 7.5) nokogiri css selector tokenizer has vulnerability (CWE-1333: Inefficient Regular Expression Complexity) affecting Duplicate Advisory libraries in the RubyGems ecosystem. The issue involves nokogiri css selector tokenizer has regular expression backtracking. Remediation is available in the latest vendor maintenance releases.

GHSA-5jhf-fpp7-v2pv at a Glance

CVE Identifier N/A
GHSA Identifier GHSA-5jhf-fpp7-v2pv
Severity HIGH
CVSS v3.1 Base Score 7.5
CWE Classification CWE-1333: Inefficient Regular Expression Complexity
Affected Product Duplicate Advisory
Package Ecosystem RubyGems
Published Date
Last Updated

Security Impact

CVSS: 7.5

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H).

Attack Vector Network (AV:N)
Attack Complexity Low (AC:L)
Privileges Required None (PR:N)
User Interaction None (UI:N)
Scope Unchanged (S:U)
Confidentiality None (C:N)
Integrity None (I:N)
Availability High (A:H)

How to Fix GHSA-5jhf-fpp7-v2pv

To remediate this vulnerability, upgrade all affected Duplicate Advisory 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: Latest secure release 
Upgrade nokogiri to Latest secure release
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-5jhf-fpp7-v2pv, inspect your project dependencies for Duplicate Advisory:

inspect dependencies for nokogiri

Analyze the terminal output to locate any version of Duplicate Advisory in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than the patched release), 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 CWE-1333: Inefficient Regular Expression Complexity, where the product uses a regular expression with a worst-case computational complexity that is inefficient and possibly exponential. In Duplicate Advisory, 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

## Duplicate Advisory This advisory has been withdrawn because it is a duplicate of GHSA-c4rq-3m3g-8wgx. This link is maintained to preserve external references. ## Original Description Nokogiri versions before 1.19.3 contain regular expression denial of service vulnerabilities in the CSS selector tokenizer affecting string-literal and identifier tokenization. Attackers can inject adversarial CSS selectors into methods like Node#css, Node#at_css, and Searchable#search to cause exponential regex backtracking and denial of service.

GHSA-5jhf-fpp7-v2pv Affected Duplicate Advisory Versions

1 component(s)
Product / Package Ecosystem Affected Versions Fixed Version
nokogiri
gem/nokogiri
RubyGems

References

GitHub Advisory / Wiki ADVISORY
https://github.com/sparklemotion/nokogiri/security/advisories/GHSA-c4rq-3m3g-8wgx
NVD — GHSA-5jhf-fpp7-v2pv NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-79770
www.vulncheck.com/advisories/nokogiri... WEB
https://www.vulncheck.com/advisories/nokogiri-before-redos-via-css-selector-tokenizer

Frequently Asked Questions

What is GHSA-5jhf-fpp7-v2pv?
GHSA-5jhf-fpp7-v2pv is a security vulnerability in Duplicate Advisory involving Nokogiri CSS selector tokenizer has regular expression backtracking under CWE-1333: Inefficient Regular Expression Complexity.
Which Duplicate Advisory versions are affected?
Affected versions include releases prior to current release patches across affected packages: nokogiri.
What version fixes GHSA-5jhf-fpp7-v2pv?
Upgrading to current release patches (or the latest patched release for your respective branch) resolves the vulnerability.
Is nokogiri affected?
Yes, nokogiri is affected in releases prior to Latest secure release. Upgrade your dependency to Latest secure release or later.
What is the CVSS score of GHSA-5jhf-fpp7-v2pv?
GHSA-5jhf-fpp7-v2pv has a CVSS v3.1 base score of 7.5 (HIGH) with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.
What CWE is associated with GHSA-5jhf-fpp7-v2pv?
GHSA-5jhf-fpp7-v2pv is classified under CWE-1333: Inefficient Regular Expression Complexity (The product uses a regular expression with a worst-case computational complexity that is inefficient and possibly exponential.).
How can I check RubyGems dependencies for GHSA-5jhf-fpp7-v2pv?
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
View Raw JSON 
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-5jhf-fpp7-v2pv",
  "modified" : "2026-09-02T14:43:13Z",
  "published" : "2026-08-25T18:31:52Z",
  "withdrawn" : "2026-09-02T14:43:13Z",
  "aliases" : [ ],
  "summary" : "Duplicate Advisory: Nokogiri CSS selector tokenizer has regular expression backtracking",
  "details" : "## Duplicate Advisory\n\nThis advisory has been withdrawn because it is a duplicate of GHSA-c4rq-3m3g-8wgx. This link is maintained to preserve external references.\n\n## Original Description\nNokogiri versions before 1.19.3 contain regular expression denial of service vulnerabilities in the CSS selector tokenizer affecting string-literal and identifier tokenization. Attackers can inject adversarial CSS selectors into methods like Node#css, Node#at_css, and Searchable#search to cause exponential regex backtracking and denial of service.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"
  }, {
    "type" : "CVSS_V4",
    "score" : "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "RubyGems",
      "name" : "nokogiri"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      } ]
    } ],
    "database_specific" : {
      "last_known_affected_version_range" : "< 1.19.3"
    }
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/sparklemotion/nokogiri/security/advisories/GHSA-c4rq-3m3g-8wgx"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-79770"
  }, {
    "type" : "WEB",
    "url" : "https://www.vulncheck.com/advisories/nokogiri-before-redos-via-css-selector-tokenizer"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-1333" ],
    "severity" : "HIGH",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-09-02T14:43:13Z",
    "nvd_published_at" : "2026-08-25T16:17:28Z"
  }
}