Integer Overflow or Wraparound Affecting nanoid package, versions <3.3.12>=4.0.0 <5.1.11
Threat Intelligence
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
Do your applications use this vulnerable package?
In a few clicks we can analyze your entire application and see what components are vulnerable in your application, and suggest you quick fixes.
Test your applications- Snyk IDSNYK-JS-NANOID-18748186
- published13 Aug 2026
- disclosed12 Aug 2026
- creditalanzabihi
Introduced: 12 Aug 2026
NewCVE-2026-73086 (opens in a new tab)How to fix?
Upgrade nanoid to version 3.3.12, 5.1.11 or higher.
Overview
Affected versions of this package are vulnerable to Integer Overflow or Wraparound through the fillPool logic in index.js and index.cjs. An attacker can make subsequent ID generation deterministic by supplying an oversized size value to nanoid(size), which is coerced into a negative 32-bit integer and corrupts the shared random pool state. After that call, all later IDs produced in the same process lose their randomness and uniqueness, breaking session tokens, CSRF tokens, and other identifiers until the process restarts.