GitHub Advisoryadvisory · npm
GHSA-mg2h-6x62-wpwc Fastify vulnerable to invalid content-type parsing, which could lead to validation bypass
HIGH
Official page ↗
- Aliases
- CVE-2025-32442
- Ecosystem
- npm
- Packages
- fastify
- Severity
- High
- CVSS vector
- CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
- Weaknesses
- CWE-1287
- Reviewed
- 2025-04-18
Affected packages
• npm fastify: >= 5.0.0, < 5.3.2 → fixed in 5.3.2
• npm fastify: >= 4.29.0, < 4.29.1 → fixed in 4.29.1
Description
Impact
In applications that specify different validation strategies for different content types, it's possible to bypass the validation by providing a _slightly altered_ content type such as with different casing or altered whitespacing before `;`.
Users using the the following pattern are affected:
```js
fastify.post('/', {
handler(request, reply) {
reply.code(200).send(request.body)
},
schema: {
body: {
content: {
'application/json': {
schema: {
type: 'object',
properties: {
'foo': {
type: 'string',
}
},
required: ['foo']
}
},
}
}
}
})
```
User using the following pattern are not affected:
```js
fastify.post('/', {
handler(request, reply) {
reply.code(200).send(request.body)
},
schema: {
body: {
type: 'object',
properties: {
'foo': {
type: 'string',
}
},
required: ['foo']
}
}
})
```
Patches
This was patched in v5.3.1, but unfortunately it did not cover all problems. This has been fully patched in v5.3.2.
Version v4.9.0 was also affected by this issue. This has been fully patched in v4.9.1.
Workarounds
Do not specify multiple content types in the schema.
References
_Are there any links users can visit to find out more?_
https://hackerone.com/reports/3087928
Related
Alias · CVE (1)
- CVE-2025-32442 Fastify is a fast and low overhead web framework, for Node.js. vulnerability
Weakness · CWE (1)
- CWE-1287 Improper Validation of Specified Type of Input weakness
References
- https://github.com/fastify/fastify/security/advisories/GHSA-mg2h-6x62-wpwc web
- https://nvd.nist.gov/vuln/detail/CVE-2025-32442 advisory
- https://github.com/fastify/fastify/commit/436da4c06dfbbb8c24adee3a64de0c51e4f47418 web
- https://github.com/fastify/fastify/commit/f3d2bcb3963cd570a582e5d39aab01a9ae692fe4 web
- https://hackerone.com/reports/3087928 web
- https://github.com/fastify/fastify package