CVE-2026-19484
HighCVSS 7.5Exploitation Probability (EPSS)
Low risk39th percentile - higher than 39% of all known CVEs
Summary
@fastify/busboy versions 3.1.0 through 3.2.0 are vulnerable to a DoS attack that stalls the Node.js event loop by sending a multipart request with a boundary of a specific length. A single small request can keep one core busy and deny service to other requests. The issue is fixed in version 3.2.1.
Risk Assessment
Risk includes disruption of Node.js-based services, potentially leading to application unavailability.
Recommendation
Upgrade @fastify/busboy to version 3.2.1 or later.
Original NVD description (English source)
@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.