Skip to content

chore(deps): update dependency nanoid to v5.1.16 [security] - #1610

Open
renovate[bot] wants to merge 1 commit into
sepoliafrom
renovate/npm-nanoid-vulnerability
Open

chore(deps): update dependency nanoid to v5.1.16 [security]#1610
renovate[bot] wants to merge 1 commit into
sepoliafrom
renovate/npm-nanoid-vulnerability

Conversation

@renovate

@renovate renovate Bot commented Aug 26, 2026

Copy link
Copy Markdown
Contributor

This PR contains the following updates:

Package Change Age Confidence
nanoid 5.1.65.1.16 age confidence

Predictable results in nanoid generation when given non-integer values

CVE-2024-55565 / GHSA-mwcw-c2x4-8c55

More information

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.

Severity

  • CVSS Score: 4.3 / 10 (Medium)
  • Vector String: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N

References

This data is provided by the GitHub Advisory Database (CC-BY 4.0).


nanoid: non-secure generators can loop indefinitely with negative size

CVE-2026-67214 / GHSA-28wg-ghj8-5hjv

More information

Details

nanoid (Nano ID) before 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.

Severity

  • CVSS Score: 8.2 / 10 (High)
  • Vector String: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

References

This data is provided by the GitHub Advisory Database (CC-BY 4.0).


nanoid: custom generators can loop indefinitely when size is zero

CVE-2026-67213 / GHSA-2v37-7h3g-55p8

More information

Details

nanoid (Nano ID) before 5.1.6 contains an infinite loop in the customAlphabet and customRandom functions. When these functions are configured with a size of 0, the internal generation loop never satisfies its exit condition and spins indefinitely, hanging the calling thread. An application that passes an unvalidated, attacker-controlled size of 0 to these functions is exposed to a denial-of-service condition.

Severity

  • CVSS Score: 8.2 / 10 (High)
  • Vector String: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

References

This data is provided by the GitHub Advisory Database (CC-BY 4.0).


nanoid: Integer Overflow or Wraparound

CVE-2026-73086 / GHSA-xwg4-73v4-xw9w

More information

Details

Summary

An integer overflow in nanoid(size) permanently corrupts the process-wide CSPRNG pool, causing all subsequent ID generation to return the deterministic string "uuuuuuuuuuuuuuuuuuuuu". Any application that passes user-influenced values to the size parameter loses all randomness guarantees for session tokens, CSRF tokens, and unique identifiers until process restart.

Details

nanoid() at index.js:101 coerces the size parameter with size |= 0, which converts it to a signed 32-bit integer. When size >= 2^31 (e.g., 2147483648), this wraps to -2147483648.

The negative value is passed to fillPool() (index.js:15):

function fillPool(bytes) {
  if (!pool || pool.length < bytes) {       // false: pool exists, -2B < pool.length
    pool = Buffer.allocUnsafe(bytes * POOL_SIZE_MULTIPLIER)
    crypto.getRandomValues(pool)
    poolOffset = 0
  } else if (poolOffset + bytes > pool.length) {  // false: poolOffset + (-2B) < pool.length
    crypto.getRandomValues(pool)
    poolOffset = 0
  }
  poolOffset += bytes  // poolOffset += -2147483648 → deeply negative
}

Neither branch triggers, so the pool is never refreshed. poolOffset becomes ~-2.1 billion.

Subsequent nanoid() calls execute:

for (let i = poolOffset - size; i < poolOffset; i++) {
  id += scopedUrlAlphabet[pool[i] & 63]
}

pool[negative_index] returns undefined. undefined & 63 evaluates to 0. urlAlphabet[0] is 'u'. Every ID becomes "uuuuuuuuuuuuuuuuuuuuu".

The corruption is persistent — it affects all subsequent calls in the process until ~100 million calls eventually wrap poolOffset back to positive, or the process restarts.

PoC
import { nanoid } from 'nanoid'

// Step 1: Normal operation
console.log(nanoid())  // e.g., "V1StGXR8_Z5jdHi6B-myT"

// Step 2: Trigger overflow (e.g., from an API parameter)
try { nanoid(2147483648) } catch(e) {}

// Step 3: All subsequent IDs are deterministic
console.log(nanoid())  // "uuuuuuuuuuuuuuuuuuuuu"
console.log(nanoid())  // "uuuuuuuuuuuuuuuuuuuuu"
console.log(nanoid())  // "uuuuuuuuuuuuuuuuuuuuu"
// ... forever, process-wide

Run with: node --experimental-vm-modules poc.mjs

Attack scenario: Any API endpoint that accepts a user-controlled length/size parameter (URL shortener slug length, configurable token size, etc.) and passes it to nanoid(userInput).

Impact

Complete loss of ID unpredictability and uniqueness, process-wide, from a single request.

  • All session IDs, CSRF tokens, API keys, and database identifiers generated after the attack are identical and predictable
  • An attacker can predict all tokens issued to other users, enabling session hijacking and authentication bypass
  • The corruption is persistent (survives across requests) and affects all consumers of nanoid in the same process
  • No special privileges or preconditions required — a single unauthenticated request is sufficient
  • Affects any application that passes external input to the size parameter without validation

Severity

  • CVSS Score: 7.4 / 10 (High)
  • Vector String: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N

References

This data is provided by the GitHub Advisory Database (CC-BY 4.0).


Release Notes

ai/nanoid (nanoid)

v5.1.16

Compare Source

v5.1.15

Compare Source

  • Fixed random pool corruption on big ID sizes.

v5.1.14

Compare Source

  • Fixed npm package size regression.

v5.1.13

Compare Source

  • Fixed npm package size regression.

v5.1.12

Compare Source

  • Moved to npm Provenance and Staged Publishing.

v5.1.11

Compare Source

  • Fixed breaking Nano ID by requesting big ID.

v5.1.10

Compare Source

v5.1.9

Compare Source

  • Fixed npm package size regression.

v5.1.8

Compare Source

v5.1.7

Compare Source


Configuration

📅 Schedule: (UTC)

  • Branch creation
    • At any time (no schedule defined)
  • Automerge
    • At any time (no schedule defined)

🚦 Automerge: Disabled by config. Please merge this manually once you are satisfied.

Rebasing: Whenever PR is behind base branch, or you tick the rebase/retry checkbox.

🔕 Ignore: Close this PR and you won't be reminded about this update again.


  • If you want to rebase/retry this PR, check this box

This PR was generated by Mend Renovate. View the repository job log.

@vercel

vercel Bot commented Aug 26, 2026

Copy link
Copy Markdown

The latest updates on your projects. Learn more about Vercel for GitHub.

Project Deployment Actions Updated (UTC)
frontends Ready Ready Preview Aug 27, 2026 10:01am

Request Review

Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment

Labels

None yet

Projects

None yet

Development

Successfully merging this pull request may close these issues.

0 participants