---
id: CVE-2021-28860
title: >-
  In Node.js mixme, prior to v0.5.1, an attacker can add or alter properties of
  an object via '__proto__' through the mutate() and merge() functions
summary: >-
  In Node.js mixme, prior to v0.5.1, an attacker can add or alter properties of
  an object via '__proto__' through the mutate() and merge() functions. The
  polluted attribute will be directly assigned to every object in the program.
  This wil…
severity: critical
cvss: 9.1
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H'
cwe:
  - CWE-1321
vendor: adaltas
product: mixme
affected:
  - mixme < 0.5.1
patched:
  - mixme 0.5.1
published: '2021-05-03'
updated: '2026-07-05'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2021-28860'
references:
  - url: >-
      https://github.com/adaltas/node-mixme/commit/cfd5fbfc32368bcf7e06d1c5985ea60e34cd4028
    label: cve@mitre.org
  - url: 'https://github.com/adaltas/node-mixme/issues/1'
    label: cve@mitre.org
  - url: >-
      https://github.com/adaltas/node-mixme/security/advisories/GHSA-79jw-6wg7-r9g4
    label: cve@mitre.org
  - url: 'https://security.netapp.com/advisory/ntap-20210618-0005/'
    label: cve@mitre.org
  - url: 'https://www.npmjs.com/~david'
    label: cve@mitre.org
  - url: 'http://nodejs.com'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: >-
      https://github.com/adaltas/node-mixme/commit/cfd5fbfc32368bcf7e06d1c5985ea60e34cd4028
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://github.com/adaltas/node-mixme/issues/1'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: >-
      https://github.com/adaltas/node-mixme/security/advisories/GHSA-79jw-6wg7-r9g4
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://security.netapp.com/advisory/ntap-20210618-0005/'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://www.npmjs.com/~david'
    label: af854a3a-2127-422b-91ae-364da2661108
tags:
  - nvd
epss: 0.01843
epssPercentile: 0.78075
ingestedAt: '2026-07-05T00:59:25.852Z'
---

## Overview

In Node.js mixme, prior to v0.5.1, an attacker can add or alter properties of an object via '__proto__' through the mutate() and merge() functions. The polluted attribute will be directly assigned to every object in the program. This will put the availability of the program at risk causing a potential denial of service (DoS).

## Affected

- `mixme < 0.5.1`

## Remediation

Upgrade past the affected range:

- `mixme 0.5.1`