Ajax requests send wrong "Content-Type" header

[brotkrueml]

• I've read and understood the contribution guidelines.
• I've searched for any related issues and avoided creating a duplicate issue.

Please give us a description of what happened.

The Ajax routes "savescores" and "prominentwords" send a HTTP request header "Content-Type" with value "text/plain". But the content in the payload is JSON, so it should be "application/json" instead to be correct.

This showed up using Modsecurity with the OWASP core rule set, as content-type in a request header with text/plain is blocked by default. As an exception rule can be defined, the correct value for the Content-Type header should be used instead.

Please describe what you expected to happen and why.

As the payload is JSON send "application/json" as Content-Type.

How can we reproduce this behavior?

Check the HTTP request header in the browser network console:

Screenshots

Technical info

• TYPO3 version: 12.4.24
• Yoast SEO version: 10.0.0
• Relevant extensions in case of a bug: -