ImageCodecException for Images Loaded via CORS Proxy After Flutter 3.22.4 Update

[poom9091]

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• I give permission for members of the FlutterFlow team to access and test my project for the sole purpose of investigating this issue.

Current Behavior

Our project uses a CORS proxy to display media files from third-party services, including Firebase Storage. This functionality worked as expected before the recent update to Flutter 3.22.4.

After the update, images from Firebase Storage that are called through the CORS proxy no longer render on our website. We are consistently receiving the following error:

ImageCodecException: Failed to detect image file format using the file header.

We have confirmed that the issue is specific to the interaction with the proxy. When we disable CORS proxy and use the direct Firebase Storage URL, the images load correctly.

This strongly suggests a regression in Flutter 3.22.4 related to how HTTP responses from a proxy are processed by the image rendering engine.

Expected Behavior

Media from Firebase and third-party sources should load correctly when called via the CORS proxy.

Steps to Reproduce

1. Create 2 new image widget to calling the media from Firebase and Third party
2. Navigate to Web Deployment
3. Enable CORS proxy and deploy function to Firebase
4. Run the project on text mode to check the result

Reproducible from Blank

• The steps to reproduce above start from a blank project.

Bug Report Code (Required)

IT40hvLqy89OxcdK+KX1bcBB/Tg5JmJ/RLsVkO5BaC0ofbbnB+w+Y/7BN0pWONO0TQh+M1m0mmcezMnemvHPFfoEJSurc4Q6+c1uazr/RlyjSpCYDc+JOW5/DZhQFVS7yra3miNTLvhvckI7wHGuCOiiRT/aK6bqIEUFBfGKMZCK2SrDX1iXc2URm05KZDPz

Visual documentation

ImageCodecException: Failed to detect image file format using the file header.

Environment

- FlutterFlow version: v6.1.11 released July 22, 2025
- Platform: Web
- Browser name and version: Chrome Version 138.0.7204.158 (Official Build) (arm64)
- Operating system and version affected: macOS Sequoia 15.5

Additional Information

No response

[Alezanello]

Hello!

Thanks for reporting this. It looks like this issue is a duplicate of the one already tracked here: Issue #6127.

Any updates or progress will be shared directly on that thread, so feel free to follow it for the latest information.