File uploads/attachments fail at 32MB despite 500MB configuration

[jeroenmarchand]

Description

Vikunja Version

v1.0.0-rc2
image: vikunja/vikunja:unstable
sha256:510cc702dfc385ed56295d4824648cd6f4b44b6095b266ce1aa7b1f62b6428d4

Browser and version

N/A (affects web interface but also reproducible via API)

OS and version

Docker (Linux containers)

What is the expected behaviour?

Files should upload successfully up to the configured 500MB limit as indicated by the /api/v1/info endpoint.

What is the actual behaviour?

File uploads fail with HTTP 400 Bad Request for files larger than exactly 33,554,432 bytes (32MB), despite Vikunja showing a 500MB limit.

Steps to reproduce the behaviour

1. Configure Vikunja with VIKUNJA_FILES_MAXSIZE: 500MB
2. Verify /api/v1/info endpoint shows "max_file_size": "500MB"
3. Create test files:

   # Exactly 32MB (works)
   dd if=/dev/zero of=test-32MB.pdf bs=1048576 count=32
   # 32.5MB (fails)  
   dd if=/dev/zero of=test-32.5MB.pdf bs=1024 count=33280

4. Upload both files via web interface:
   • test-32MB.pdf (33,554,432 bytes) → Works
   • test-32.5MB.pdf (34,078,720 bytes) → Does not work

Additional information

• Exact boundary: Files ≤ 33,554,432 bytes work, files > 33,554,432 bytes fail
• 32MB significance: 33,554,432 equals 32 << 20 (common default for HTTP parsing)
• No reverse proxy: Direct access to Vikunja
• Configuration verified: /api/v1/info correctly shows 500MB limit

This suggests the issue may be related to HTTP framework multipart parsing limits that need to be aligned with Vikunja's configured file size limit.

Vikunja Version

v1.0.0-rc2

Browser and version

N/A (affects web interface but also reproducible via API)

Can you reproduce the bug on the Vikunja demo site?

No

Screenshots

No response