nanoid (Nano ID) before 3.3.16 and 5.1.16 contains an infinite loop in the customAlphabet and nanoid functions of its non-secure module (…
CVE-2026-67214 · GHSA-28wg-ghj8-5hjv · EUVD-2026-50326 · published 29 Jul 2026
How serious is it
- Severity: high, CVSS score 8.2 out of 10.
- No exploit prediction (EPSS) score yet.
- Not on the CISA list of exploited vulnerabilities.
- No public exploit in Exploit-DB.
Is your app affected by CVE-2026-67214?
Paste this prompt into Claude Code, Cursor or any AI coding tool: it runs a free Shippable scan of your project and fixes what it finds. Built with Lovable, Bolt or v0? Scan your live app. Or upload your package file.
Who is affected
- nanoid: 0 <3.3.16
- nanoid: 4.0.0 <5.1.16
How to check
- Find out whether you run the affected product and which version, then compare it with the versions above.
How to fix
Copies a prompt for Claude Code, Cursor or Codex that asks it to check whether you run this product.
- Apply the vendor's update or mitigation from the references below. If there is none yet, limit exposure of the affected service until there is.
- If a vulnerable version was live, check your logs and rotate the secrets that server could read.
The advisory
nanoid (Nano ID) before 3.3.16 and 5.1.16 contains an infinite loop in the customAlphabet and nanoid functions of its non-secure module (nanoid/non-secure). When these functions are given a negative size, the loop counter is decremented from a negative value and never reaches its termination condition, spinning indefinitely and hanging the calling thread. An application that passes an unvalidated, attacker-controlled negative size to these functions is exposed to a denial-of-service condition.
Check your whole app
Dependencies are only half of it. Free and read-only: before you push, run npx shippable-dev scan localhost:3000 in your project folder, no account needed. For your live app, you prove it's yours with a one-line tag first.
References
- github.com/ai/nanoid/releases/tag/5.1.16
- github.com/ai/nanoid/releases/tag/3.3.16
- github.com/ai/nanoid/commit/6ccc67bbaba71d3d77a21d9b636f4171a268ce49
- www.vulncheck.com/advisories/nanoid-before-infinite-loop-via-negative-size-in-non-secure-module
Merged from ENISA EUVD. Last updated 30 Oct 2026. All vulnerabilities · RSS · JSON