GHSA-g9cg-h3jm-cwrc: @hapi/pez Prototype Pollution Vulnerability

HIGH
Share
CWE-1321
Published
Advisory Summary

GHSA-g9cg-h3jm-cwrc is a HIGH prototype pollution vulnerability (CWE-1321: Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution')) affecting @hapi/pez libraries in the npm ecosystem. The issue involves prototype pollution in @hapi/subtext. Remediation is available by upgrading affected packages to version 5.0.1.

GHSA-g9cg-h3jm-cwrc at a Glance

CVE Identifier N/A
GHSA Identifier GHSA-g9cg-h3jm-cwrc
Severity HIGH
CVSS v3.1 Base Score N/A
CWE Classification CWE-1321: Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution')
Affected Product @hapi/pez
Package Ecosystem npm
Published Date
Last Updated

How to Fix GHSA-g9cg-h3jm-cwrc

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

@hapi/pez fixed: 5.0.1 
npm install @hapi/pez@5.0.1
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 @hapi/pez

How to Check if You Are Affected

To determine whether your Node.js application is affected by GHSA-g9cg-h3jm-cwrc, inspect your project dependencies using npm:

npm ls @hapi/pez

Analyze the terminal output to locate any version of @hapi/pez in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 5.0.1), your application is affected.

Note: The npm ls @hapi/pez 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 @hapi/pez, 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

Versions of `@hapi/pez` prior to 4.1.2 or 5.0.1 are vulnerable to Prototype Pollution. A multipart payload can be constructed in a way that one of the parts’ content can be set as the entire payload object’s prototype. If this prototype contains data, it may bypass other validation rules which enforce access and privacy. If this prototype evaluates to null, it can cause unhandled exceptions when the request payload is accessed. ## Recommendation Upgrade to versions 5.0.1 or later. There is a fix available for version 4.1.2, but it only available for direct download from the repository.

GHSA-g9cg-h3jm-cwrc Affected @hapi/pez Versions

1 component(s)
Fixed Versions:
5.0.1
Product / Package Ecosystem Affected Versions Fixed Version
@hapi/pez
npm/@hapi/pez
npm
< 5.0.1
5.0.1

References

@hapi/pez Source Repository REPOSITORY
https://github.com/hapijs/pez
www.npmjs.com/advisories/1480 WEB
https://www.npmjs.com/advisories/1480

Frequently Asked Questions

What is GHSA-g9cg-h3jm-cwrc?
GHSA-g9cg-h3jm-cwrc is a security vulnerability in @hapi/pez involving Prototype Pollution in @hapi/subtext under CWE-1321: Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution').
Which @hapi/pez versions are affected?
Affected versions include releases prior to 5.0.1 across affected packages: @hapi/pez.
What version fixes GHSA-g9cg-h3jm-cwrc?
Upgrading to 5.0.1 (or the latest patched release for your respective branch) resolves the vulnerability.
Is @hapi/pez affected?
Yes, @hapi/pez is affected in releases prior to 5.0.1. Upgrade your dependency to 5.0.1 or later.
What CWE is associated with GHSA-g9cg-h3jm-cwrc?
GHSA-g9cg-h3jm-cwrc 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 GHSA-g9cg-h3jm-cwrc?
Run the dependency tree command: 'npm ls @hapi/pez'. 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-g9cg-h3jm-cwrc",
  "modified" : "2025-09-26T23:12:03Z",
  "published" : "2020-09-03T15:47:23Z",
  "aliases" : [ ],
  "summary" : "Prototype Pollution in @hapi/subtext",
  "details" : "Versions of `@hapi/pez` prior to 4.1.2 or 5.0.1 are vulnerable to Prototype Pollution. A multipart payload can be constructed in a way that one of the parts’ content can be set as the entire payload object’s prototype. If this prototype contains data, it may bypass other validation rules which enforce access and privacy. If this prototype evaluates to null, it can cause unhandled exceptions when the request payload is accessed.\n\n## Recommendation\n\nUpgrade to versions 5.0.1 or later. There is a fix available for version 4.1.2,  but it only available for direct download from the repository.",
  "severity" : [ ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "npm",
      "name" : "@hapi/pez"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "5.0.1"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "PACKAGE",
    "url" : "https://github.com/hapijs/pez"
  }, {
    "type" : "WEB",
    "url" : "https://www.npmjs.com/advisories/1480"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-1321" ],
    "severity" : "HIGH",
    "github_reviewed" : true,
    "github_reviewed_at" : "2020-08-31T19:00:51Z",
    "nvd_published_at" : null
  }
}