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@fastify/busboy vulnerable to CRLF injection via multipart Content-Disposition filename and name

Type: advisorySource: OSV1 source record

### 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.

Announced Group revision 1
Original source ↗

GHSA-gxm5-99cw-xjw9

Primary source · Revision 1

Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.

Security context

Source reference: osv:GHSA-gxm5-99cw-xjw9

@fastify/busboy

Source reference: /affected/0/package/name

Affected versions
Not stated in this record
Fixed versions
3.2.2

Source reference: /affected/0/ranges

Prerequisites
Not stated in this record

Structured affected-version data

Original package identities and version rules from this source.

[
  {
    "ranges": [
      {
        "type": "SEMVER",
        "events": [
          {
            "introduced": "0"
          },
          {
            "fixed": "3.2.2"
          }
        ]
      }
    ],
    "package": {
      "name": "@fastify/busboy",
      "purl": "pkg:npm/%40fastify/busboy",
      "ecosystem": "npm"
    },
    "database_specific": {
      "source": "https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/10/GHSA-gxm5-99cw-xjw9/GHSA-gxm5-99cw-xjw9.json"
    }
  }
]
Related CVEs
CVE-2026-74866

Source reference: /aliases

Publisher severity

medium

Source reference: /severity/0/score

Event
#85825 · Revision 1
Added to Heist Feed
Publisher date
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