Check to detect when an endpoint support other content types than JSON.

[righettod]

Description

Hi,

This PR propose a BCheck to verify if an endpoint, supporting the content type JSON, also support other content types like XML/YAML. The usage context is an web API that normally consume JSON but also, via the web framework used, support XML/YAML. This can open new attack vectors like for example XML external entity (XXE) injection.

Thank you for your feedback 😉

Tests

It was tested in Burp Pro version 2025.12.4:

BCheck Contributions

• BCheck compiles and executes as expected
• BCheck contains appropriate metadata (name, version, author, description and appropriate tags)
• Only .bcheck files have been added or modified
• BCheck is in the appropriate folder
• PR contains single or limited number of BChecks (Multiple PRs are preferred)
• BCheck attempts to minimize false positives

[PortSwiggerWiener]

Many thanks for the PR. The BCheck looks good.

[righettod]

Many thanks for the PR. The BCheck looks good.

Thanks a lot for the quick feedback and Burp 🥰