CVE-2025-8101: Linkifyjs Cross-Site Scripting Vulnerability

HIGH
Advisory Identifier: GHSA-95jq-xph2-cx9h
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CWE-1321
Published
Advisory Summary

CVE-2025-8101 is a HIGH cross-site scripting vulnerability (CWE-1321: Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution')) affecting Linkifyjs libraries in the npm ecosystem. The issue involves linkify allows prototype pollution & html attribute injection (xss). Remediation is available by upgrading affected packages to version 4.3.2.

CVE-2025-8101 at a Glance

CVE Identifier CVE-2025-8101
GHSA Identifier GHSA-95jq-xph2-cx9h
Severity HIGH
CVSS v3.1 Base Score N/A
CWE Classification CWE-1321: Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution')
Affected Product Linkifyjs
Package Ecosystem npm
Published Date
Last Updated

How to Fix CVE-2025-8101

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

linkifyjs fixed: 4.3.2 
npm install linkifyjs@4.3.2
Verify Direct and Transitive Dependencies

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

npm ls linkifyjs

How to Check if You Are Affected

To determine whether your Node.js application is affected by CVE-2025-8101, inspect your project dependencies using npm:

npm ls linkifyjs

Analyze the terminal output to locate any version of Linkifyjs in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 4.3.2), your application is affected.

Note: The npm ls linkifyjs command inspects dependencies declared in your package.json and lockfile; it does not perform automated runtime dynamic scanning.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-1321: Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution'), where the product receives input from an upstream component that specifies attributes that are to be initialized or updated in an object, but it does not properly control modifications of attributes of the object prototype. In Linkifyjs, 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

Prototype Pollution in internal `assign()` helper in Linkify allows remote attackers to execute arbitrary JavaScript (Stored or Reflected XSS) via injection of event handlers through unfiltered proto property. This issue affects Linkify version 4.3.1 and is fixed in 4.3.2.

CVE-2025-8101 Affected Linkifyjs Versions

1 component(s)
Fixed Versions:
4.3.2
Product / Package Ecosystem Affected Versions Fixed Version
linkifyjs
npm/linkifyjs
npm
≥ 4.3.1
< 4.3.2
All 1 versions
4.3.1
4.3.2

References

NVD — CVE-2025-8101 NVD
https://nvd.nist.gov/vuln/detail/CVE-2025-8101
Security Fix Commit FIX COMMIT
https://github.com/nfrasser/linkifyjs/commit/931d3e28b68951b8f898ea4d6504696346b485b0
caverav.cl/posts/linkify-xss/l... WEB
https://caverav.cl/posts/linkify-xss/linkify-xss
fluidattacks.com/advisories/charly WEB
https://fluidattacks.com/advisories/charly
Linkifyjs Source Repository REPOSITORY
https://github.com/nfrasser/linkifyjs
Linkifyjs Release RELEASE
https://github.com/nfrasser/linkifyjs/releases/tag/v4.3.2
www.npmjs.com/package/linkifyjs WEB
https://www.npmjs.com/package/linkifyjs

Frequently Asked Questions

What is CVE-2025-8101?
CVE-2025-8101 is a security vulnerability in Linkifyjs involving Linkify Allows Prototype Pollution & HTML Attribute Injection (XSS) under CWE-1321: Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution').
Which Linkifyjs versions are affected?
Affected versions include releases prior to 4.3.2 across affected packages: linkifyjs.
What version fixes CVE-2025-8101?
Upgrading to 4.3.2 (or the latest patched release for your respective branch) resolves the vulnerability.
Is linkifyjs affected?
Yes, linkifyjs is affected in releases prior to 4.3.2. Upgrade your dependency to 4.3.2 or later.
What CWE is associated with CVE-2025-8101?
CVE-2025-8101 is classified under CWE-1321: Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution') (The product receives input from an upstream component that specifies attributes that are to be initialized or updated in an object, but it does not properly control modifications of attributes of the object prototype.).
How can I check npm dependencies for CVE-2025-8101?
Run the dependency tree command: 'npm ls linkifyjs'. 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-95jq-xph2-cx9h",
  "modified" : "2026-06-26T20:26:11Z",
  "published" : "2025-07-26T00:30:32Z",
  "aliases" : [ "CVE-2025-8101" ],
  "summary" : "Linkify Allows Prototype Pollution & HTML Attribute Injection (XSS)",
  "details" : "Prototype Pollution in internal `assign()` helper in Linkify allows remote attackers to execute arbitrary JavaScript (Stored or Reflected XSS) via injection of event handlers through unfiltered proto property. This issue affects Linkify version 4.3.1 and is fixed in 4.3.2.",
  "severity" : [ {
    "type" : "CVSS_V4",
    "score" : "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:H/VA:L/SC:N/SI:N/SA:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "npm",
      "name" : "linkifyjs"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "4.3.1"
      }, {
        "fixed" : "4.3.2"
      } ]
    } ],
    "versions" : [ "4.3.1" ]
  } ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2025-8101"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/nfrasser/linkifyjs/commit/931d3e28b68951b8f898ea4d6504696346b485b0"
  }, {
    "type" : "WEB",
    "url" : "https://caverav.cl/posts/linkify-xss/linkify-xss"
  }, {
    "type" : "WEB",
    "url" : "https://fluidattacks.com/advisories/charly"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/nfrasser/linkifyjs"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/nfrasser/linkifyjs/releases/tag/v4.3.2"
  }, {
    "type" : "WEB",
    "url" : "https://www.npmjs.com/package/linkifyjs"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-1321" ],
    "severity" : "HIGH",
    "github_reviewed" : true,
    "github_reviewed_at" : "2025-07-29T19:09:33Z",
    "nvd_published_at" : "2025-07-25T22:15:25Z"
  }
}