GitHub Advisoryadvisory · npm

GHSA-gxm5-99cw-xjw9 @fastify/busboy vulnerable to CRLF injection via multipart Content-Disposition filename and name

MEDIUM Published 2026-10-05 Modified 2026-10-05 Official page ↗
Aliases
CVE-2026-74866
Ecosystem
npm
Packages
@fastify/busboy
Severity
Moderate
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N
Weaknesses
CWE-93
Reviewed
2026-10-05

Affected packages

• npm @fastify/busboy: < 3.2.2 → fixed in 3.2.2

Description

Impact `@fastify/busboy` 3.2.1 and earlier retains a bare carriage return or line feed inside the parsed `Content-Disposition` parameters returned to the application. The multipart header parser ends a header line only on the two-byte `\r\n` sequence, so a lone CR or LF embedded in a part header is carried verbatim into the `filename` and field `name` delivered by the `file` and `field` events. An application that forwards the supplied filename or name into a CR/LF-sensitive sink cannot anticipate the embedded control character. An attacker who uploads a file whose `filename` or field `name` contains a bare CR or LF can pollute filenames on disk when the upload is saved under its original name, inject forged lines into logs, or inject headers on a downstream hop that does not re-validate CR/LF, such as object-storage metadata or a proxied backend. Applications using `@fastify/busboy` directly, or through `@fastify/multipart` and its consumers, are affected. Patches Upgrade to `@fastify/busboy` 3.2.2 or later. Workarounds Validate or strip carriage return and line feed characters from the `filename` and field `name` before using them in any filesystem, logging, or outbound-header context.

Related

Alias · CVE (1)

  • CVE-2026-74866 @fastify/busboy is a multipart form-data parser for Node.js. vulnerability

Weakness · CWE (1)

  • CWE-93 Improper Neutralization of CRLF Sequences weakness

References