GHSA-g64q-3vg8-8f93: Pez Prototype Pollution Vulnerability

HIGH
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CWE-1321
Published
Advisory Summary

GHSA-g64q-3vg8-8f93 is a HIGH prototype pollution vulnerability (CWE-1321: Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution')) affecting Pez libraries in the npm ecosystem. The issue involves prototype pollution in pez. Remediation is available in the latest vendor maintenance releases.

GHSA-g64q-3vg8-8f93 at a Glance

CVE Identifier N/A
GHSA Identifier GHSA-g64q-3vg8-8f93
Severity HIGH
CVSS v3.1 Base Score N/A
CWE Classification CWE-1321: Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution')
Affected Product Pez
Package Ecosystem npm
Published Date
Last Updated

How to Fix GHSA-g64q-3vg8-8f93

To remediate this vulnerability, upgrade all affected 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.

pez fixed: Latest secure release 
npm install pez@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: 

npm ls pez

How to Check if You Are Affected

To determine whether your Node.js application is affected by GHSA-g64q-3vg8-8f93, inspect your project dependencies using npm:

npm ls pez

Analyze the terminal output to locate any version of Pez 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: The npm ls 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 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

All versions of `pez` 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 This package is deprecated and is now maintained as `@hapi/pez`. Please update your dependencies to use `@hapi/pez`.

GHSA-g64q-3vg8-8f93 Affected Pez Versions

1 component(s)
Product / Package Ecosystem Affected Versions Fixed Version
pez
npm/pez
npm
≥ 0.0.0

References

Pez Source Repository REPOSITORY
https://github.com/hapijs/pez/compare/v4.1.1...v4.1.2
www.npmjs.com/advisories/1479 WEB
https://www.npmjs.com/advisories/1479

Frequently Asked Questions

What is GHSA-g64q-3vg8-8f93?
GHSA-g64q-3vg8-8f93 is a security vulnerability in Pez involving Prototype Pollution in pez under CWE-1321: Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution').
Which Pez versions are affected?
Affected versions include releases prior to current release patches across affected packages: pez.
What version fixes GHSA-g64q-3vg8-8f93?
Upgrading to current release patches (or the latest patched release for your respective branch) resolves the vulnerability.
Is pez affected?
Yes, pez is affected in releases prior to Latest secure release. Upgrade your dependency to Latest secure release or later.
What CWE is associated with GHSA-g64q-3vg8-8f93?
GHSA-g64q-3vg8-8f93 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-g64q-3vg8-8f93?
Run the dependency tree command: 'npm ls 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-g64q-3vg8-8f93",
  "modified" : "2025-09-30T16:16:58Z",
  "published" : "2020-09-03T15:47:10Z",
  "aliases" : [ ],
  "summary" : "Prototype Pollution in pez",
  "details" : "All versions of `pez` 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\n## Recommendation\n\nThis package is deprecated and is now maintained as `@hapi/pez`. Please update your dependencies to use `@hapi/pez`.",
  "severity" : [ ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "npm",
      "name" : "pez"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0.0.0"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/hapijs/pez/compare/v4.1.1...v4.1.2"
  }, {
    "type" : "WEB",
    "url" : "https://www.npmjs.com/advisories/1479"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-1321" ],
    "severity" : "HIGH",
    "github_reviewed" : true,
    "github_reviewed_at" : "2020-08-31T19:00:49Z",
    "nvd_published_at" : null
  }
}