Upload an attachment to a card API broken after updating to Nextcloud v33.0.5 & Deck v1.17.3

[user8446]

Describe the bug
Upload an attachment to a card using the Deck API is broken. Uploading an attachment to the card using the web UI still works. Other Deck API's still work as well such as sort and creating a new card. Our scripts and nothing else has changed.

To Reproduce
Steps to reproduce the behavior:

1. Upload an attachment to a card using the Deck API
   POST /boards/{boardId}/stacks/{stackId}/cards/{cardId}/attachments - Upload an attachment
2. Response is 400 bad request

cURL response:

* [HTTP/2] [1] OPENED stream for https://<redacted>/index.php/apps/deck/api/v1.1/boards/14/stacks/181/cards/1224/attachments
* [HTTP/2] [1] [:method: POST]
* [HTTP/2] [1] [:scheme: https]
* [HTTP/2] [1] [:authority: <redacted>]
* [HTTP/2] [1] [:path: /index.php/apps/deck/api/v1.1/boards/14/stacks/181/cards/1224/attachments]
* [HTTP/2] [1] [authorization: Basic <redacted>]
* [HTTP/2] [1] [user-agent: curl/8.20.0]
* [HTTP/2] [1] [ocs-apirequest: true]
* [HTTP/2] [1] [accept: application/json]
* [HTTP/2] [1] [content-length: 440407]
* [HTTP/2] [1] [content-type: multipart/form-data; boundary=------------------------Dw51QLq05ZgIYYHQzFX05u]
> POST /index.php/apps/deck/api/v1.1/boards/14/stacks/181/cards/1224/attachments HTTP/2
> Host: <redacted>
> Authorization: <redacted>
> User-Agent: curl/8.20.0
> OCS-APIRequest: true
> Accept: application/json
> Content-Length: 440407
> Content-Type: multipart/form-data; boundary=------------------------Dw51QLq05ZgIYYHQzFX05u
> 
* upload completely sent off: 440407 bytes
< HTTP/2 400 
< date: Fri, 12 Jun 2026 15:05:43 GMT
< server: Apache

Nextcloud v33.0.5
Deck v1.17.3
Ubuntu server 24.04.4 LTS
MySQL 8.4.9
PHP 8.3.31