{"id":"CVE-2026-74866","aliases":["CLSA-2026-1792746654","EUVD-2026-63829","GHSA-gxm5-99cw-xjw9"],"status":"published","title":"@fastify/busboy vulnerable to CRLF injection via multipart Content-Disposition filename and name","description":"@fastify/busboy is a multipart form-data parser for Node.js. Its multipart part-header parser splits header lines only on the two-byte carriage-return line-feed sequence, so a lone carriage return or line feed embedded in a part header is not treated as a line break and is carried verbatim into the parsed Content-Disposition filename and field name handed to the application. An attacker who uploads a file whose filename or field name contains a bare carriage return or line feed can inject control characters into consumers that trust the parser to return clean values, enabling filesystem filename pollution, log forging, or header injection when the value is forwarded to a carriage-return-sensitive sink. All versions of @fastify/busboy up to and including 3.2.1 are affected. The issue is fixed in version 3.2.2, which rejects any header line that still contains a bare carriage return or line feed. Users should upgrade to 3.2.2, and consumers such as @fastify/multipart should bump their @fastify/busboy dependency to pull in the fix.","severity":{"version":"3.1","score":5.8,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N","level":"medium","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-12","score":0.00326,"percentile":0.26053,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":true},"cwes":["CWE-93"],"published":"2026-08-21T08:20:32Z","modified":"2026-10-28T02:31:05Z","fixes":[{"ecosystem":"npm","package":"@fastify/busboy","fixed_in":["3.2.2"],"sources":["ghsa","osv"]}],"affected":[{"source":"ghsa","ecosystem":"npm","package":"@fastify/busboy","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"3.2.2"}]}]},{"source":"osv","ecosystem":"TuxCare:npm","package":"@fastify/busboy","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"2.1.1-tuxcare.0"},{"fixed":"2.1.1-tuxcare.1"}]}],"versions":["2.1.1"],"bundled":2},{"source":"osv","ecosystem":"npm","package":"@fastify/busboy","ranges":[{"type":"SEMVER","events":[{"introduced":"0"},{"fixed":"3.2.2"}]}]}],"products":[{"vendor":"@fastify/busboy","product":"@fastify/busboy"},{"vendor":"fastify","product":"fastify\\/busyboy"}],"references":[{"url":"https://github.com/fastify/busboy/security/advisories/GHSA-gxm5-99cw-xjw9","tags":["Vendor Advisory","advisory","web"]},{"url":"https://cna.openjsf.org/security-advisories.html","tags":["Third Party Advisory","advisory","web"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-74866","tags":["advisory"]},{"url":"https://github.com/fastify/busboy/commit/cc7da17c5c88d79c314a9e149a79e5a00a6c23be","tags":["web"]},{"url":"https://github.com/fastify/busboy/releases/tag/v3.2.2","tags":["web"]},{"url":"https://github.com/advisories/GHSA-gxm5-99cw-xjw9"},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/74xxx/CVE-2026-74866.json","tags":["advisory"]},{"url":"https://github.com/fastify/busboy","tags":["package"]}],"sources":{"cve":[{"id":"CVE-2026-74866","title":"@fastify/busboy vulnerable to CRLF injection via multipart Content-Disposition filename and name","description":"@fastify/busboy is a multipart form-data parser for Node.js. Its multipart part-header parser splits header lines only on the two-byte carriage-return line-feed sequence, so a lone carriage return or line feed embedded in a part header is not treated as a line break and is carried verbatim into the parsed Content-Disposition filename and field name handed to the application. An attacker who uploads a file whose filename or field name contains a bare carriage return or line feed can inject control characters into consumers that trust the parser to return clean values, enabling filesystem filename pollution, log forging, or header injection when the value is forwarded to a carriage-return-sensitive sink. All versions of @fastify/busboy up to and including 3.2.1 are affected. The issue is fixed in version 3.2.2, which rejects any header line that still contains a bare carriage return or line feed. Users should upgrade to 3.2.2, and consumers such as @fastify/multipart should bump their @fastify/busboy dependency to pull in the fix.","status":"published","published":"2026-08-21T08:20:32.672Z","modified":"2026-08-21T12:37:26.259Z","cvss":[{"version":"3.1","score":5.8,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N","level":"medium","assessor":"cna"}],"cwes":["CWE-93"],"updated_at":"2026-11-02T14:20:03.081354Z"}],"euvd":[{"id":"EUVD-2026-63829","description":"@fastify/busboy is a multipart form-data parser for Node.js. Its multipart part-header parser splits header lines only on the two-byte carriage-return line-feed sequence, so a lone carriage return or line feed embedded in a part header is not treated as a line break and is carried verbatim into the parsed Content-Disposition filename and field name handed to the application. An attacker who uploads a file whose filename or field name contains a bare carriage return or line feed can inject control characters into consumers that trust the parser to return clean values, enabling filesystem filename pollution, log forging, or header injection when the value is forwarded to a carriage-return-sensitive sink. All versions of @fastify/busboy up to and including 3.2.1 are affected. The issue is fixed in version 3.2.2, which rejects any header line that still contains a bare carriage return or line feed. Users should upgrade to 3.2.2, and consumers such as @fastify/multipart should bump their @fastify/busboy dependency to pull in the fix.","status":"published","published":"2026-08-21T08:20:32Z","modified":"2026-08-21T12:37:26Z","cvss":[{"version":"3.1","score":5.8,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N","level":"medium"}],"updated_at":"2026-11-02T18:01:37.96401Z"}],"ghsa":[{"id":"GHSA-gxm5-99cw-xjw9","title":"@fastify/busboy vulnerable to CRLF injection via multipart Content-Disposition filename and name","description":"### Impact\n\n`@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.\n\nAn 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.\n\n### Patches\n\nUpgrade to `@fastify/busboy` 3.2.2 or later.\n\n### Workarounds\n\nValidate 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.","status":"published","published":"2026-10-05T22:33:44Z","modified":"2026-10-05T22:33:45Z","cvss":[{"version":"3.1","score":5.8,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N","level":"medium"}],"cwes":["CWE-93"],"updated_at":"2026-11-02T14:41:25.889593Z"}],"nvd":[{"id":"CVE-2026-74866","description":"@fastify/busboy is a multipart form-data parser for Node.js. Its multipart part-header parser splits header lines only on the two-byte carriage-return line-feed sequence, so a lone carriage return or line feed embedded in a part header is not treated as a line break and is carried verbatim into the parsed Content-Disposition filename and field name handed to the application. An attacker who uploads a file whose filename or field name contains a bare carriage return or line feed can inject control characters into consumers that trust the parser to return clean values, enabling filesystem filename pollution, log forging, or header injection when the value is forwarded to a carriage-return-sensitive sink. All versions of @fastify/busboy up to and including 3.2.1 are affected. The issue is fixed in version 3.2.2, which rejects any header line that still contains a bare carriage return or line feed. Users should upgrade to 3.2.2, and consumers such as @fastify/multipart should bump their @fastify/busboy dependency to pull in the fix.","status":"published","published":"2026-08-21T09:16:40.89Z","modified":"2026-10-16T15:10:00.103Z","cvss":[{"version":"3.1","score":5.8,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N","level":"medium","assessor":"secondary"}],"cwes":["CWE-93"],"updated_at":"2026-11-02T14:12:40.665005Z"}],"osv":[{"id":"CVE-2026-74866","title":"@fastify/busboy vulnerable to CRLF injection via multipart Content-Disposition filename and name","description":"@fastify/busboy is a multipart form-data parser for Node.js. Its multipart part-header parser splits header lines only on the two-byte carriage-return line-feed sequence, so a lone carriage return or line feed embedded in a part header is not treated as a line break and is carried verbatim into the parsed Content-Disposition filename and field name handed to the application. An attacker who uploads a file whose filename or field name contains a bare carriage return or line feed can inject control characters into consumers that trust the parser to return clean values, enabling filesystem filename pollution, log forging, or header injection when the value is forwarded to a carriage-return-sensitive sink. All versions of @fastify/busboy up to and including 3.2.1 are affected. The issue is fixed in version 3.2.2, which rejects any header line that still contains a bare carriage return or line feed. Users should upgrade to 3.2.2, and consumers such as @fastify/multipart should bump their @fastify/busboy dependency to pull in the fix.","status":"published","published":"2026-08-21T08:20:32.672Z","modified":"2026-10-28T02:31:05.591254117Z","cvss":[{"version":"3.1","score":5.8,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N","level":"medium"}],"cwes":["CWE-93"],"updated_at":"2026-11-02T15:45:16.748692Z"},{"id":"GHSA-gxm5-99cw-xjw9","title":"@fastify/busboy vulnerable to CRLF injection via multipart Content-Disposition filename and name","description":"### Impact\n\n`@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.\n\nAn 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.\n\n### Patches\n\nUpgrade to `@fastify/busboy` 3.2.2 or later.\n\n### Workarounds\n\nValidate 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.","status":"published","published":"2026-10-05T22:33:44Z","modified":"2026-10-05T22:45:04.558942837Z","cvss":[{"version":"3.1","score":5.8,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N","level":"medium"}],"cwes":["CWE-93"],"updated_at":"2026-11-02T15:46:48.546324Z"},{"id":"CLSA-2026-1792746654","title":"TuxCare security update for @fastify/busboy (2 CVEs)","description":"TuxCare rebuilt @fastify/busboy to address 2 CVEs. Fixed in 2.1.1-tuxcare.1.","status":"published","published":"2026-10-23T09:10:54Z","modified":"2026-10-23T13:45:35.083688752Z","updated_at":"2026-11-02T15:43:54.981307Z"}]}}