---
id: CVE-2026-102992
title: piscina is a node.js worker pool implementation
summary: >-
  piscina is a node.js worker pool implementation. Prior to 4.9.4, 5.3.2, and
  6.0.0-rc.5, Piscina stores ThreadPool.options in src/index.ts as a plain
  object that inherits from Object.prototype. Applications with a separate
  prototype-pollu…
severity: critical
cvss: 9.2
cvssVector: 'CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N'
cwe:
  - CWE-1321
vendor: piscinajs
product: piscina
affected:
  - piscina < 4.9.4
  - 'piscina >= 5.0.0, < 5.3.2'
  - 'piscina >= 6.0.0-rc.1, < 6.0.0-rc.5'
published: '2026-09-30'
updated: '2026-09-30'
sourceUpdated: '2026-09-30T21:17:06.450'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-102992'
references:
  - url: >-
      https://github.com/piscinajs/piscina/commit/0cb12fca37f526065b072592afe954574dcc656f
    label: security-advisories@github.com
  - url: >-
      https://github.com/piscinajs/piscina/commit/2f69f67159a0e48b38fd61fa4a91c2fdc19fff72
    label: security-advisories@github.com
  - url: >-
      https://github.com/piscinajs/piscina/commit/5be7bbb19e3787bb698862cd516121a578d690f7
    label: security-advisories@github.com
  - url: >-
      https://github.com/piscinajs/piscina/commit/bebbda255c2981cecddd36b171b94be2fd41c9a6
    label: security-advisories@github.com
  - url: 'https://github.com/piscinajs/piscina/releases/tag/v4.9.4'
    label: security-advisories@github.com
  - url: 'https://github.com/piscinajs/piscina/releases/tag/v5.3.2'
    label: security-advisories@github.com
  - url: 'https://github.com/piscinajs/piscina/releases/tag/v6.0.0-rc.5'
    label: security-advisories@github.com
  - url: >-
      https://github.com/piscinajs/piscina/security/advisories/GHSA-67c8-pqhq-4rmx
    label: security-advisories@github.com
  - url: >-
      https://github.com/piscinajs/piscina/security/advisories/GHSA-67c8-pqhq-4rmx
    label: 134c704f-9b21-4f2e-91b3-4a467353bcc0
tags:
  - nvd
  - cve.org
  - exploit-available
exploitAvailable: true
ssvc:
  exploitation: poc
  automatable: 'no'
  technicalImpact: total
  timestamp: '2026-09-30T20:47:28.974211Z'
cvssSource: cna
ingestedAt: '2026-09-30T20:23:19.514Z'
---

## Overview

piscina is a node.js worker pool implementation. Prior to 4.9.4, 5.3.2, and 6.0.0-rc.5, Piscina stores ThreadPool.options in src/index.ts as a plain object that inherits from Object.prototype. Applications with a separate prototype-pollution primitive can therefore supply inherited values for security-sensitive options that do not have own defaults. An inherited execArgv value is passed to the Node.js Worker constructor and can preload attacker-controlled code in worker threads, an inherited loadBalancer function can execute during task scheduling, and inherited env values can alter worker environments. This issue is fixed in versions 4.9.4, 5.3.2, and 6.0.0-rc.5.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.