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.

There are packages installed that are affected by a vulnerability referenced in the following CVE:

  - 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.
    (CVE-2026-55388)

ID	Name	Product	Family	Type	Severity
461550	Echo: piscina: security update to 4.9.3	Tenable Cloud Security	Echo Local Security Checks	Local	high
461550	Echo: piscina: security update to 4.9.3	Tenable Self-Hosted Container Security	Echo Local Security Checks	Local	high
443862	SCA: security update for piscina (GHSA-x9g3-xrwr-cwfg)	Tenable Cloud Security	SCA Checks	Local	high
443862	SCA: security update for piscina (GHSA-x9g3-xrwr-cwfg)	Tenable Self-Hosted Container Security	SCA Checks	Local	high

Detections

Analytics

CVE-2026-55388

high

Tenable Plugins

high

high

high

high