MediumGHSA-mwcw-c2x4-8c55CVE-2024-55565

Predictable results in nanoid generation when given non-integer values

Published 9 Dec 2024 · Updated 10 Sept 2026

Affected packages

nanoidnpm

Affected: >=4.0.0 <5.0.9
Fixed in: 5.0.9

Update to the fixed version for your release line, for example:npm install nanoid@5.0.9

nanoidnpm

Affected: <3.3.8
Fixed in: 3.3.8

Update to the fixed version for your release line, for example:npm install nanoid@3.3.8

Details

When nanoid is called with a fractional value, there were a number of undesirable effects:

1. in browser and non-secure, the code infinite loops on while (size--) 2. in node, the value of poolOffset becomes fractional, causing calls to nanoid to return zeroes until the pool is next filled 3. if the first call in node is a fractional argument, the initial buffer allocation fails with an error

Version 3.3.8 and 5.0.9 are fixed.

Is GHSA-mwcw-c2x4-8c55 in any of your client repos?

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References

Advisory data from OSV.dev (opens OSV.dev in a new tab), refreshed daily.