Cloudanix VulnDB

CVE-2026-55388

High · 8.1

CVSS

8.1

EPSS

0.5%

Published

Jun 22, 2026

CISA due date

—

The record

piscina is a node.js worker pool implementation. Prior to 6.0.0-rc.2, 5.2.0, and 4.9.3, piscina's constructor and run() paths read the filename option via plain member access. Both reads fall through the prototype chain when the caller's options object doesn't have filename as an own property. When Object.prototype.filename is polluted upstream the inherited value flows to worker_threads.Worker import and the attacker's .mjs runs in the worker. This vulnerability is fixed in 6.0.0-rc.2, 5.2.0, and 4.9.3.

Affected packages

Ecosystem Package Introduced Fixed
npm piscina 0 4.9.3
npm piscina 5.0.0-alpha.0 5.2.0
npm piscina 6.0.0-rc.1 6.0.0-rc.2

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