CVE-2026-55388 Details
Description
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.
A prototype pollution vulnerability has been identified in Piscina, a Node.js worker pool implementation, affecting versions prior to 6.0.0-rc.2, 5.2.0, and 4.9.3. The vulnerability arises because the library's constructor and run() methods access the filename option through standard member access. This approach allows inherited values to be exploited when the options object does not contain filename as an own property. If Object.prototype.filename is manipulated, the altered value can be passed to worker_threads.Worker, executing the attacker's .mjs file in the worker environment.
Users can upgrade to Piscina versions 6.0.0-rc.2, 5.2.0, or 4.9.3, where this vulnerability has been fixed.
Metrics
CVSS 4.0 Severity and Vector Strings:
VolerionCVSS 3.x Severity and Vector Strings:
No data available for CVSS Version 2.0 on this CVE.
Volerion
Assessed Jun 22, 2026CISA-ADP
Assessed Jun 23, 2026References to Advisories, Solutions, and Tools
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| URL | Source(s) | Tag(s) |
|---|---|---|
| https://github.com/piscinajs/piscina/security/advisories/GHSA-x9g3-xrwr-cwfg | CISA-ADP | AdvisoryExploitRemedyTechnical AnalysisVendor |
| https://github.com/piscinajs/piscina/security/advisories/GHSA-x9g3-xrwr-cwfg | [email protected] | AdvisoryExploitRemedyTechnical AnalysisVendor |
Weakness Enumeration
| CWE-ID | CWE Name | Source |
|---|---|---|
| CWE-1321 | Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution') | [email protected] |
| CWE-94 | Improper Control of Generation of Code ('Code Injection') | [email protected] |
Affected Products
| Product | Versions |
|---|---|
| piscina | <= 5.1.4 (semver) <= 4.9.2 (semver) <= 6.0.0-rc.1 (semver) |
CPE
Remediation
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Change History
2 change records found show changes
| Date | Action | Recorded By |
|---|---|---|
| Jun 23, 2026 | CVE Modified | CISA-ADP |
| Jun 22, 2026 | New CVE Received | [email protected] |