Infinite loop in nanoid - CVE-2026-67213

Vulnerability details

The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.

The vulnerability exists due to 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. A remote attacker can consume all available system resources and cause denial of service conditions.

Affected software

How to mitigate CVE-2026-67213

External References

• 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

Related Security Bulletins

• Infinite loop in nanoid (Nano ID)
• Multiple vulnerabilities in IBM Netezza Appliance - Cyclops