Disclosure summary
### 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 outbou
Source-specific records & product guidance
Sources retain their own attribution and scoring. Follow the original record to confirm affected versions, fixed releases, and configuration conditions.
GitHub Reviewed Security Advisories · GHSA-gxm5-99cw-xjw9
Open original source · Updated Oct 05, 2026
@fastify/busboy vulnerable to CRLF injection via multipart Content-Disposition filename and name
Source severity: MEDIUM / 0
| Ecosystem | Package | Affected range | First patched |
|---|---|---|---|
| npm | @fastify/busboy | < 3.2.2 | 3.2.2 |
Original records & references
- NIST NVD record
- CVE Program record
- github.com — Reviewed advisory
PUBLISHED 2026-10-05T18:33:44-04:00
MODIFIED 2026-10-05T18:33:45-04:00
INGESTED 2026-10-06T11:45:33-04:00