{"id":"GHSA-2v37-7h3g-55p8","summary":"nanoid: custom generators can loop indefinitely when size is zero","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.","aliases":["CVE-2026-67213"],"modified":"2026-08-13T16:02:08.036514186Z","published":"2026-07-29T15:31:12Z","database_specific":{"github_reviewed_at":"2026-08-07T20:50:34Z","nvd_published_at":"2026-07-29T14:16:34Z","cwe_ids":["CWE-835"],"severity":"HIGH","github_reviewed":true},"references":[{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-67213"},{"type":"WEB","url":"https://github.com/ai/nanoid/commit/cb3626d0f3342fdf179cd425fd9c4fbb92c7d0e7"},{"type":"WEB","url":"https://github.com/ai/nanoid/commit/e10f8d40ce9d1ab47f66d65a16b48086432730d0"},{"type":"WEB","url":"https://github.com/ai/nanoid/commit/f9d13f150847d117877adee3460a46eceb0cf49b"},{"type":"PACKAGE","url":"https://github.com/ai/nanoid"},{"type":"WEB","url":"https://github.com/ai/nanoid/releases/tag/3.3.17"},{"type":"WEB","url":"https://github.com/ai/nanoid/releases/tag/3.3.18"},{"type":"WEB","url":"https://github.com/ai/nanoid/releases/tag/5.1.6"},{"type":"WEB","url":"https://www.vulncheck.com/advisories/nanoid-before-infinite-loop-via-zero-size-in-customalphabet-and-customrandom"}],"affected":[{"package":{"name":"nanoid","ecosystem":"npm","purl":"pkg:npm/nanoid"},"ranges":[{"type":"SEMVER","events":[{"introduced":"0"},{"fixed":"3.3.18"}]}],"database_specific":{"source":"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/07/GHSA-2v37-7h3g-55p8/GHSA-2v37-7h3g-55p8.json"}},{"package":{"name":"nanoid","ecosystem":"npm","purl":"pkg:npm/nanoid"},"ranges":[{"type":"SEMVER","events":[{"introduced":"4.0.0"},{"fixed":"5.1.6"}]}],"database_specific":{"source":"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/07/GHSA-2v37-7h3g-55p8/GHSA-2v37-7h3g-55p8.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H"},{"type":"CVSS_V4","score":"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"}]}