Hacktoberfest 2026: the issues maintainers tagged for October, open and beginner-friendly. Browse Hacktoberfest issues

JSON:API: request documents with no `data`, no `type` or a wrong `type` are accepted with 201

Open
  • Is something wrong?
#8,703 0 comments 0 reactions 0 assignees View on GitHub

Maintainers usually reply within 1 day

Nobody has claimed this yet.

Assessment

Difficulty
3/5
Estimated time
1-2 days
Newbie friendliness
62/100
Issue type
Bug
Clarity
Clearly specified
Activity status
Active
Tech stack
php
Domain
api

Research direction

Start in src/JsonApi/Serializer, where JsonApi\Serializer\ItemNormalizerTrait::denormalize() reads $data['data']['attributes'] ?? [] and $data['data']['relationships'] ?? [] without checking the document shape. Reproduce with the request bodies in the table (for example "Y", {"title":"A"} and a mismatched type) against a POST /novels operation. Done means malformed documents return 400 Bad Request, and a POST whose type does not match the endpoint returns 409 Conflict, with the existing JSON:API tests still passing.

Written by the indexing model from the issue text.

Description

API Platform version(s) affected

4.4.4

Description

The JSON:API denormalizer does not check the structure of the request document. A body that is not a valid JSON:API document is accepted, and the resource is created with its default values.

The spec requires:

  • the top level of a request document is an object with a data member (document structure),
  • data is a resource object with a type member, and attributes is an object (resource objects),
  • "A server MUST return 409 Conflict when processing a POST request in which the resource object's type is not among the type(s) that constitute the collection represented by the endpoint" (creating resources).

JsonApi\Serializer\ItemNormalizerTrait::denormalize() reads $data['data']['attributes'] ?? [] and $data['data']['relationships'] ?? [], and it does not check the other members.

How to reproduce
#[ApiResource(operations: [
    new Get(provider: [self::class, 'provide']),
    new Post(processor: [self::class, 'process']),
])]
final class Novel
{
    public int $id = 1;
    public string $title = 'Dune';

    public static function provide(): self { return new self(); }
    public static function process(self $data, Operation $operation): self { return $data; }
}

Each of these POST /novels bodies answers 201 Created:

Body Problem
"Y" not an object
42 not an object
{"title":"A"} no data member
{"data":"x"} data is not a resource object
{"data":{"type":"Novel","attributes":["x"]}} attributes is not an object
{"data":{"attributes":{"title":"A"}}} no type member
{"data":{"type":"Author","attributes":{"title":"A"}}} type does not match the endpoint

Response for "Y":

{"data":{"id":"/novels/1","type":"Novel","attributes":{"_id":1,"title":"Dune"}}}

A validation constraint on a required property hides the problem in some cases, but a resource with optional properties or defaults is created from any body.

Expected:

  • A body that is not a JSON:API document, or has no data object, no type or a non-object attributes/relationships: 400 Bad Request.
  • A type that does not match the resource on POST: 409 Conflict.
Additional Context

Checked on api-platform/core v4.4.4, Symfony 7.4, PHP 8.5, in an empty Symfony app. The related code in src/JsonApi/Serializer is the same on main, except for the error status cast (#8366).

The app has only FrameworkBundle, TwigBundle and ApiPlatformBundle, with this config:

$c->extension('api_platform', [
    'mapping' => ['paths' => ['%kernel.project_dir%/src/ApiResource']],
    'formats' => ['jsonapi' => ['application/vnd.api+json']],
    'error_formats' => ['jsonapi' => ['application/vnd.api+json'], 'jsonproblem' => ['application/problem+json']],
    'doctrine' => ['enabled' => false],
]);

All requests send Accept: application/vnd.api+json and, when they have a body, Content-Type: application/vnd.api+json. The responses are from the prod environment.

Dominant language
PHP
Stars
2.6k
Forks
989
Avg merge
1d 22h
Merged PRs (30d)
100

Getting set up

First steps

  1. Read the whole issue, then the project's contributing guide.
  2. Comment on the issue to say you are picking it up — it saves two people doing the same work.
  3. Fork the repository and make your change on a branch.
  4. Open a pull request that references the issue number.

More from api-platform/core

All issues in api-platform/core

Similar issues

More PHP issues

Get new issues in your inbox

A short digest of beginner-friendly GitHub issues.