REST API 413 entity too large for POST /rest/api/2/issue/{issueIdOrKey}/attachments

Summary

Using REST API to upload issue attachment POST /rest/api/2/issue/{issueIdOrKey}/attachments may result in 413 Entity too large response, even if it is allowed to have bigger uploads. However later on the attachment can be seen as attached to the issue.

Steps to reproduce

1. use REST API endpoint to upload an attachment to a Jira issue: POST /rest/api/2/issue/{issueIdOrKey}/attachments
2. select a file that is large - usually the bug affects files larger than 120MB, but there is no precise size threshold.
3. make sure that file size does not exceed the attachment size allowed for the instance.

Expected Results

1. REST API response is 200 OK including representation of attached file in the response body.
2. File is successfully attached to the issue.

Actual Results

1. REST API response is 413 Entity too large
2. File is successfully attached to the issue.

Workaround

After receiving the 413 Entity too large response to attachment upload request, use GET /rest/api/2/issue/{issueIdOrKey} endpoint to fetch issue details and confirm whether the file was attached, together with the attachment details.