@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.
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History
Thu, 13 Aug 2026 09:30:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Description | @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. | |
| Title | @fastify/busboy vulnerable to Denial of Service via oversized multipart boundary | |
| Weaknesses | CWE-1322 CWE-835 |
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| Metrics |
cvssV3_1
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Status: PUBLISHED
Assigner: openjs
Published:
Updated: 2026-08-13T08:50:47.361Z
Reserved: 2026-08-10T16:17:07.041Z
Link: CVE-2026-19484
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Status : Received
Published: 2026-08-13T10:17:11.640
Modified: 2026-08-13T10:17:11.640
Link: CVE-2026-19484
No data.
OpenCVE Enrichment
Updated: 2026-08-13T10:30:04Z