CVE-2026-74866Medium· 5.8▾ Sunlit@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 i…
▾ Sunlit zone — Low / medium · no exploitation signal
impact 31.9 · likelihood 0.1 · exploitation 0
Need a working PoC? Pro members can cast a request and our team develops one — it lands right here.
Exploit-prediction probability, daily snapshots since Sep 8.
Disclosure to exploitation, from the record and what we observed since indexing it.
Disclosed via NVD
0.2%
0.2% → 0.3%
Last analysed / modified upstream
@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.
fastify/busyboy < 3.2.2Upgrade past the affected range:
fastify/busyboy 3.2.2Affected packages:
@fastify/busboy < 3.2.2Patched in:
@fastify/busboy 3.2.2Connected by shared product, vendor, weakness, or advisory.
CVE-2026-92081Medium· 5.9fastify is a fast and low-overhead web framework for Node.js
CVE-2026-84504High· 8.1fastify versions before 5.12.2 treat the object resolved by a successful Ajv async validator as the value result protocol used by custom validator compilers
CVE-2026-84469High· 7.5fastify versions before 5.12.2 decide whether to compile a request schema based on JavaScript truthiness, but JSON Schema Draft 7 defines the boolean false as a valid schema that rejects every instance
CVE-2026-84428High· 7.5fastify versions before 5.12.2 implement the case-insensitive nature of HTTP header names by lowercasing names in a route's header schema before compiling it, but the transformation is incomplete: it lowercases the properties keys and th…
CVE-2026-76169High· 7.5fastify versions >= 4.0.0 and before 5.12.2 can route a malformed URL sent under one plugin prefix to the custom not-found handler of a different sibling plugin, and invoke it without the preHandler hook declared for that handler
CVE-2026-15074High· 7.5@fastify/static vulnerable to route guard bypass via path traversal