CVE-2026-55388: CWE-94: Improper Control of Generation of Code ('Code Injection') in piscinajs piscina
CVE-2026-55388 is a high-severity code injection vulnerability in the piscina Node.js worker pool library. Versions prior to 4.9.3 and between 4.9.3 and before 5.2.0 are affected. The vulnerability arises because the constructor and run() methods read the filename option via plain member access, which falls through the prototype chain if the caller's options object lacks an own filename property. If Object.prototype.filename is polluted, an attacker can cause arbitrary .mjs code to run in a worker thread. This issue is fixed in versions 4.9.3, 5.2.0, and later.
AI Analysis
Technical Summary
The vulnerability in piscina involves improper control of code generation (CWE-94) due to prototype pollution of Object.prototype.filename. When the filename option is accessed without checking own properties, an attacker can inject a malicious module path that is loaded and executed by worker_threads.Worker. This allows arbitrary code execution within the worker thread context. The flaw affects piscina versions prior to 4.9.3 and versions from 4.9.3 up to but not including 5.2.0. The issue is resolved in piscina versions 4.9.3, 5.2.0, and 6.0.0-rc.2 and later.
Potential Impact
Successful exploitation allows an attacker to execute arbitrary code in a worker thread by injecting a malicious module filename via prototype pollution. This leads to full confidentiality, integrity, and availability impact on the affected system components running piscina. The CVSS 3.1 score is 8.1 (High), reflecting network attack vector, high complexity, no privileges required, no user interaction, and high impact on confidentiality, integrity, and availability.
Mitigation Recommendations
A fix is available in piscina versions 4.9.3, 5.2.0, and 6.0.0-rc.2 and later. Users should upgrade to one of these versions or newer to remediate this vulnerability. Patch status is confirmed by the version information in the advisory. No other mitigations are specified.
CVE-2026-55388: CWE-94: Improper Control of Generation of Code ('Code Injection') in piscinajs piscina
Description
CVE-2026-55388 is a high-severity code injection vulnerability in the piscina Node.js worker pool library. Versions prior to 4.9.3 and between 4.9.3 and before 5.2.0 are affected. The vulnerability arises because the constructor and run() methods read the filename option via plain member access, which falls through the prototype chain if the caller's options object lacks an own filename property. If Object.prototype.filename is polluted, an attacker can cause arbitrary .mjs code to run in a worker thread. This issue is fixed in versions 4.9.3, 5.2.0, and later.
CVSS v3.1
Score 8.1high
Affected software
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AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
The vulnerability in piscina involves improper control of code generation (CWE-94) due to prototype pollution of Object.prototype.filename. When the filename option is accessed without checking own properties, an attacker can inject a malicious module path that is loaded and executed by worker_threads.Worker. This allows arbitrary code execution within the worker thread context. The flaw affects piscina versions prior to 4.9.3 and versions from 4.9.3 up to but not including 5.2.0. The issue is resolved in piscina versions 4.9.3, 5.2.0, and 6.0.0-rc.2 and later.
Potential Impact
Successful exploitation allows an attacker to execute arbitrary code in a worker thread by injecting a malicious module filename via prototype pollution. This leads to full confidentiality, integrity, and availability impact on the affected system components running piscina. The CVSS 3.1 score is 8.1 (High), reflecting network attack vector, high complexity, no privileges required, no user interaction, and high impact on confidentiality, integrity, and availability.
Mitigation Recommendations
A fix is available in piscina versions 4.9.3, 5.2.0, and 6.0.0-rc.2 and later. Users should upgrade to one of these versions or newer to remediate this vulnerability. Patch status is confirmed by the version information in the advisory. No other mitigations are specified.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- GitHub_M
- Date Reserved
- 2026-06-16T18:57:40.183Z
- Cvss Version
- 3.1
- State
- PUBLISHED
- Remediation Level
- null
Threat ID: 6a39735deed863c81e3962f6
Added to database: 06/22/2026, 17:39:41 UTC
Last enriched: 06/22/2026, 17:54:09 UTC
Last updated: 06/23/2026, 01:50:06 UTC
Views: 6
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