# What changed in piscina

> 3 changes in piscina 5 from its official release notes, upgrade guides and advisories: 1 security, 1 new APIs and options. Each one cited. Sources checked 2026-10-18. HTML: https://unstale.sh/npm/piscina/

To see which of these apply to a repository, run `npx @unstale/cli init` in it.

## piscina 5

### Security

- piscina: Prototype-pollution gadget in ThreadPool.options allows RCE via execArgv / loadBalancer / env (4.9.4, 5.3.2) — [security advisory](https://github.com/advisories/GHSA-67C8-PQHQ-4RMX)

### New APIs and options

- Adds the stricterFIFO option for queue fairness. (5.3.0) — [release notes](https://github.com/piscinajs/piscina/releases/tag/v5.3.0)

### Fixes and other changes

- Standardizes the normalization calculation for standard deviation. (5.1.4) — [release notes](https://github.com/piscinajs/piscina/releases/tag/v5.1.4)