{"id":"CVE-2026-19484","summary":"@fastify/busboy vulnerable to Denial of Service via oversized multipart boundary","details":"@fastify/busboy is a multipart form-data parser. In versions 3.1.0 through 3.2.0, a remote unauthenticated attacker can stall the Node.js event loop by sending a multipart request whose boundary is crafted to a specific length. The vendored streaming search stores its skip table in a fixed 256 entry byte array, and a boundary of exactly 252 bytes makes the search needle 256 bytes, which truncates the default skip distance to zero and turns the search into a CPU bound loop on a small body. A single small request can keep one core busy and deny service to other requests handled by the same process. The issue is fixed in @fastify/busboy 3.2.1, which widens the skip table so the skip distance is preserved. Users should upgrade to 3.2.1.","aliases":["GHSA-xjh9-v7x6-24jw"],"modified":"2026-08-15T11:45:47.395008278Z","published":"2026-08-13T08:50:47.361Z","database_specific":{"cna_assigner":"openjs","cwe_ids":["CWE-1322","CWE-835"],"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/19xxx/CVE-2026-19484.json"},"references":[{"type":"ADVISORY","url":"https://cna.openjsf.org/security-advisories.html"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/19xxx/CVE-2026-19484.json"},{"type":"ADVISORY","url":"https://github.com/fastify/busboy/security/advisories/GHSA-xjh9-v7x6-24jw"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-19484"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/fastify/busboy","events":[{"introduced":"be7065f4e663a89a7c0006841fd1fb59dabfe4ca"},{"fixed":"b404d602fe173809e5e71bf0b46132c656844047"}],"database_specific":{"source":["AFFECTED_FIELD","DESCRIPTION"],"extracted_events":[{"introduced":"3.1.0"},{"fixed":"3.2.1"},{"fixed":"3.2.0"}]}}],"versions":["v3.2.0","v3.1.1","v3.1.0"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-19484.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"}]}