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

[renovate]

This PR contains the following updates:

Package	Change	Age	Confidence
nanoid	5.1.6 → 5.1.16

---

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

• https://nvd.nist.gov/vuln/detail/CVE-2026-67214
• https://github.com/ai/nanoid/commit/6ccc67bbaba71d3d77a21d9b636f4171a268ce49
• https://github.com/ai/nanoid/releases/tag/5.1.16
• https://www.vulncheck.com/advisories/nanoid-before-infinite-loop-via-negative-size-in-non-secure-module
• https://github.com/ai/nanoid/pull/600
• https://github.com/ai/nanoid/pull/601
• https://github.com/ai/nanoid/commit/e835c9b71eab832bc6106944bdd26ea96cf2c66d
• https://github.com/advisories/GHSA-28wg-ghj8-5hjv

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

• https://nvd.nist.gov/vuln/detail/CVE-2026-67213
• https://github.com/ai/nanoid/commit/cb3626d0f3342fdf179cd425fd9c4fbb92c7d0e7
• https://github.com/ai/nanoid/releases/tag/5.1.6
• https://www.vulncheck.com/advisories/nanoid-before-infinite-loop-via-zero-size-in-customalphabet-and-customrandom
• https://github.com/ai/nanoid/commit/f9d13f150847d117877adee3460a46eceb0cf49b
• https://github.com/ai/nanoid/releases/tag/3.3.17
• https://github.com/ai/nanoid/commit/e10f8d40ce9d1ab47f66d65a16b48086432730d0
• https://github.com/ai/nanoid/releases/tag/3.3.18
• https://github.com/advisories/GHSA-2v37-7h3g-55p8

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

• https://github.com/ai/nanoid/security/advisories/GHSA-xwg4-73v4-xw9w
• https://nvd.nist.gov/vuln/detail/CVE-2026-73086
• https://github.com/ai/nanoid/commit/7087969281cab8ba8ae3babf1894e819068b3bb4
• https://github.com/ai/nanoid/commit/821dfed7b5db7f88e92f56c60eef32c8135077c3
• https://github.com/ai/nanoid/commit/b0036ed60dc9facd7f1191a50dfb3076500202ac
• https://github.com/ai/nanoid/releases/tag/3.3.12
• https://github.com/ai/nanoid/releases/tag/5.1.11
• https://github.com/advisories/GHSA-xwg4-73v4-xw9w

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

---

Release Notes

ai/nanoid (nanoid)

v5.1.16

Compare Source

• Fixed forever loop on negative size (by @​spokodev).

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

• Fixed breaking Nano ID by requesting big ID (by @​alanzabihi).

v5.1.9

Compare Source

• Fixed npm package size regression.

v5.1.8

Compare Source

• Made cusatomAlphabet 75% faster (by @​saripovdenis).

v5.1.7

Compare Source

• Added --version to CLI (by @​mahmoodhamdi).
• Updated nanoid.js for CDN (by @​mahmoodhamdi).
• Fixed docs (by @​mahmoodhamdi).
• Fixed customRandom types (by @​oguimbal).

---

Configuration

📅 Schedule: (in timezone UTC)

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

🚦 Automerge: Enabled.

♻ 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]

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

Project	Deployment	Actions	Updated
fragments	Ready	Preview	Oct 13, 2026 7:29pm UTC