ZAP Breakpoint alters request body encoding (UTF-8 Thai text becomes unreadable)

[anno]

Hi, I’m encountering an issue when using breakpoints in ZAP.

My original request body is:

{"message": "สวัสดี"}

But when I intercept it using a breakpoint, ZAP displays/changes it to something like:

{"message": "สวัสดี"}

It looks like the UTF-8 Thai characters are being decoded incorrectly (possibly interpreted as Latin-1 or Windows-1252).

Thanks in advance!


this is a curl I get from chrome 

curl 'http://localhost:3000/greeting' \

-H 'Accept: application/json' \

-H 'Accept-Language: en-US,en;q=0.9' \

-H 'Cache-Control: no-cache' \

-H 'Content-Type: application/json' \

-H 'Origin: http://127.0.0.1:5500' \

-H 'Pragma: no-cache' \

-H 'Proxy-Connection: keep-alive' \

-H 'Referer: http://127.0.0.1:5500/' \

-H 'Sec-Fetch-Dest: empty' \

-H 'Sec-Fetch-Mode: cors' \

-H 'Sec-Fetch-Site: cross-site' \

-H 'User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/142.0.0.0 Safari/537.36' \

-H 'sec-ch-ua: "Chromium";v="142", "Google Chrome";v="142", "Not_A Brand";v="99"' \

-H 'sec-ch-ua-mobile: ?0' \

-H 'sec-ch-ua-platform: "macOS"' \

--data-raw '{"message": "สวัสดี"}'

[thc202]

Hi,

This should be fixed in the latest weekly releases:
https://www.zaproxy.org/download/#weekly

Let us know if it works better for you.

Best regards.

[anno]

Hi,

Thanks for the update. I’ve tried the latest weekly release (version: ZAP_WEEKLY_D-2025-11-04.zip), but the issue still occurs.

When I intercept the request, the UTF-8 Thai characters are still being displayed as garbled text

Thanks again for your support.