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

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

High npm
Severity
8.2 / 10
High · CVSS 4.0
Exploit chance (EPSS)
0.33%
Chance of exploitation in the next 30 days. Higher than 26.15% of scored vulnerabilities.
Known exploited
No
Not in CISA's catalog
Weakness
CWE-835 Loop with Unreachable Exit Condition ('Infinite Loop')
Fix
3.3.16
Upgrade nanoid to this version or later

Description

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.

Affected versions

npm

PackageVulnerableFixed in
nanoid
< 3.3.16
3.3.16
nanoid
>= 4.0.0, < 5.1.16
5.1.16
nanoid
< 3.3.16
3.3.16
nanoid
>= 4.0.0, < 5.1.16
5.1.16

How to fix

Move to the fixed version or later with your package manager, update the lockfile, and run your tests. If the package only arrives through another dependency, upgrade that dependency first. If none of its releases pulls a fixed version yet, force the version with your package manager's override.

nanoid npm → 3.3.16

npm
npm install nanoid@3.3.16
yarn
yarn add nanoid@3.3.16
pnpm
pnpm add nanoid@3.3.16

Severity breakdown

CVSS 4.0 8.2

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

Attack vector
Network
Attack complexity
Low
Attack requirements
Present
Privileges required
None
User interaction
None
Confidentiality (vulnerable system)
None
Integrity (vulnerable system)
None
Availability (vulnerable system)
High
Confidentiality (subsequent systems)
None
Integrity (subsequent systems)
None
Availability (subsequent systems)
None

CVSS 3.1 5.9

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H

Attack vector
Network
Attack complexity
High
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

Weakness

CWE-835: Loop with Unreachable Exit Condition ('Infinite Loop')

The product contains an iteration or loop with an exit condition that cannot be reached, i.e., an infinite loop.

References

Timeline

  1. Published
  2. Last updated by the source
  3. Latest EPSS score
AdvisorySeverityWhy it's related
GHSA-xwg4-73v4-xw9w
nanoid: Integer Overflow or Wraparound
High Also affects nanoid
GHSA-2v37-7h3g-55p8
nanoid: custom generators can loop indefinitely when size is zero
High Also affects nanoid
GHSA-mwcw-c2x4-8c55
Predictable results in nanoid generation when given non-integer values
Medium Also affects nanoid
GHSA-qrpm-p2h7-hrv2
Exposure of Sensitive Information to an Unauthorized Actor in nanoid
Medium Also affects nanoid
GHSA-5849-834g-hvw5
pypdf has possible infinite loop when hitting EOF in standard xref table during trailer search
High Same weakness, CWE-835
GHSA-mfr5-77xh-9j7h
pypdf has possible infinite loop when cloning dictionaries
High Same weakness, CWE-835
GHSA-h6cr-wjv9-3cpp
Forge: Denial of Service via infinite loop in BigInteger.modInverse() with negative input (incomplete fix of CVE-2026-33891)
Low Same weakness, CWE-835
GHSA-fw5c-8223-6h42
russh: peer-declared zero maximum packet size permanently stalls channel writes (silent AsyncWrite hang)
Medium Same weakness, CWE-835
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