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.
CVE-2026-67214
CVSS base score
5.9 (v3.1)
Severity
MEDIUM
Attack vector
Network
Weakness
CWE-835
Last modified
October 29, 2026
CVSS vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
Affected products
nanoid project nanoid
References
- github.com Patch
- github.com Product, Release Notes
- github.com Product, Release Notes
- www.vulncheck.com Patch, Release Notes, Third Party Advisory