Inquiry Regarding 403 Error on REST API Attachment Upload (Jira v9.12.26)

[mg l]

Hello, Jira Support Team,

We are currently using a self-hosted Jira server, version v9.12.26#9120026.

I am writing to inquire about an issue I'm encountering with the REST API for handling attachments.

Here is the situation:

1. My goal is to download an attachment from a specific Jira ticket and then upload it to a different ticket using the REST API.

2. I have confirmed with our internal Jira administrator, and they have stated that there are no specific restrictions configured on their end that should prevent this action.

3. While I can successfully download the attachment via the REST API, the upload process fails with the following HTTP 403 error: JIRAError: JiraError HTTP 403 ... text : You are not allowed to upload this file type. Please get your Jira admin to update the Attachment Checker configration

Could you please clarify whether this is a known bug in Jira version 9.12.26, or if this error definitively points to a server-side configuration issue that our administrator may need to adjust?

Thank you for your assistance.

Best regards,

[Florian Bonniec]

HI @mg l 

What endpoint are you using ?

403 should be returned if attachments is disabled or if you don't have permission to add attachments to this issue. Most likely you do not have permission in the project. But, you may have an app that filter attachment that are added to the ticket.

Do you have such app installed on your jira instance ?

Regards

[mg l]

Hello,

Thank you for your response. Based on your feedback, I'd like to provide more context about the issue.

• Permissions Confirmed: I am the project lead for the relevant project, so a lack of permissions is not the cause of this problem.

• Working API Functions: My Python script, using token-based authentication, is already functioning correctly for several REST API operations. This includes creating and cloning tickets, as well as downloading attachments from existing tickets.

• Specific Point of Failure: The issue occurs specifically in the re-upload process. The workflow is as follows:

  1. Successfully download an existing attachment (such as a .ppt, .mp4, or .docx file) from one ticket via the REST API.

  2. Attempt to upload that same file to a different ticket via the REST API. This is when the 403 error occurs.

Given that basic permissions are not the issue and other API calls are successful, your suggestion seems very relevant.

My question is: Does this situation strongly suggest that a specific plugin or a custom configuration on our company's internal Jira server is actively blocking these file uploads only when they originate from a REST API call?

[Florian Bonniec]

The error suggest that you have this app installed 

https://marketplace.atlassian.com/apps/1211257/attachment-checker-for-jira?tab=overview

Regards