piscina: Prototype-pollution gadget in ThreadPool.options allows RCE via execArgv / loadBalancer / env
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- High
- Attack requirements
- Present
- Impact type
- —
- Confidentiality · integrity · availability
- High · High · High
- Fix status
- Fixed
Attack profile from CVSS 4.0 · CNA. Fix status from CNA and GitHub.
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-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.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- Poc
- Automatable
- No
- Technical impact
- Total
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| piscinajs | piscina | before 4.9.4; 5.0.0 to before 5.3.2; 6.0.0-rc.1 to before 6.0.0-rc.5 | 4.9.4, 5.3.2, 6.0.0-rc.5 | Patch available | CNA |
| — | piscina (npm) | 5.0.0 to before 5.3.2 | 5.3.2 | Patch available | GHSA-67c8-pqhq-4rmx |
| — | piscina (npm) | before 4.9.4 | 4.9.4 | Patch available | GHSA-67c8-pqhq-4rmx |
| — | piscina (npm) | 6.0.0-rc.1 to before 6.0.0-rc.5 | 6.0.0-rc.5 | Patch available | GHSA-67c8-pqhq-4rmx |
- piscina Vendorpiscinajs Affected before 4.9.4; 5.0.0 to before 5.3.2; 6.0.0-rc.1 to before 6.0.0-rc.5 Fixed in 4.9.4, 5.3.2, 6.0.0-rc.5 Patch available CNA
- piscina (npm) Vendor— Affected 5.0.0 to before 5.3.2 Fixed in 5.3.2 Patch available GHSA-67c8-pqhq-4rmx
- piscina (npm) Vendor— Affected before 4.9.4 Fixed in 4.9.4 Patch available GHSA-67c8-pqhq-4rmx
- piscina (npm) Vendor— Affected 6.0.0-rc.1 to before 6.0.0-rc.5 Fixed in 6.0.0-rc.5 Patch available GHSA-67c8-pqhq-4rmx
Remediation
- Fix · CNA piscina (piscinajs) Fixed in 4.9.4, 5.3.2, 6.0.0-rc.5
- Fix · GHSA-67c8-pqhq-4rmx piscina (npm) Fixed in 5.3.2 Advisory →
- Fix · GHSA-67c8-pqhq-4rmx piscina (npm) Fixed in 4.9.4 Advisory →
- Fix · GHSA-67c8-pqhq-4rmx piscina (npm) Fixed in 6.0.0-rc.5 Advisory →
Vendor assessments
Timeline
- 2026-10-02 Threatist record created from CVE-2026-102992
- 2026-10-03 Alias added: GHSA-67c8-pqhq-4rmx
- 2026-10-10 Affected versions changed · Red Hat
- 2026-10-10 CVSS score added · Red Hat
References
Other 9
- https://github.com/piscinajs/piscina/security/advisories/GHSA-67c8-pqhq-4rmx
- https://github.com/piscinajs/piscina/commit/0cb12fca37f526065b072592afe954574dcc656f
- https://github.com/piscinajs/piscina/commit/2f69f67159a0e48b38fd61fa4a91c2fdc19fff72
- https://github.com/piscinajs/piscina/commit/5be7bbb19e3787bb698862cd516121a578d690f7
- https://github.com/piscinajs/piscina/commit/bebbda255c2981cecddd36b171b94be2fd41c9a6
- https://github.com/piscinajs/piscina/releases/tag/v4.9.4
- https://github.com/piscinajs/piscina/releases/tag/v5.3.2
- https://github.com/piscinajs/piscina/releases/tag/v6.0.0-rc.5
- https://github.com/piscinajs/piscina
More piscinajs vulnerabilities
- TI-2026-39959 piscina: Prototype Pollution Gadget → RCE via inherited options.filename CVSS 3.1HIGH 8.1
Sources
- CVE-2026-102992 · CVE Program
- CVE-2026-102992 · NVD
- FIRST EPSS
- GHSA-67c8-pqhq-4rmx · GitHub Advisory Database · CC BY 4.0
- CVE-2026-102992 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences