GHSA-2v37-7h3g-55p8 nanoid: custom generators can loop indefinitely when size is zero

• npm nanoid: < 3.3.18 → fixed in 3.3.18 • npm nanoid: >= 4.0.0, < 5.1.6 → fixed in 5.1.6

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.