Media / Attachments REST API endpoint: cast args to array before sending to wp_slash > wp_insert_attachment

[ramonjd]

Problem

The prepare_item_for_database() method returns an object, but wp_slash() expects a string or array. Without casting the object to an array, wp_slash() would return the object unchanged, meaning string values within the object wouldn't be properly escaped for database insertion.

Props to @justlevine for spotting it

Solution

Cast the object to an array before passing it to wp_slash():

// Before
$new_attachment_id = wp_insert_attachment( wp_slash( $new_attachment_post ), $saved['path'], 0, true );

// After  
$new_attachment_id = wp_insert_attachment( wp_slash( (array) $new_attachment_post ), $saved['path'], 0, true );

Testing

Ensure no regressions to the media/edit endpoint.

• In the block editor, add an image block, then edit the image using the cropper
• Verify the image is saved correctly.

Kapture.2025-10-25.at.12.55.35.mp4

To be sure, you can copy that network request as cURL or fetch and add a title or description with apostrophes to the body payload, e.g.,

 "body": "{\"src\":\"http://localhost:4013/wp-content/uploads/2025/10/homemade-smash-burgers-1-edited.jpg\",\"modifiers\":[{\"type\":\"rotate\",\"args\":{\"angle\":90}}],\"title\": \"burger'licious\"}",

The results of wp_slash( (array) $new_attachment_post ) should be

Array ( 'post_title' => burger\\'licious...

Unit tests

Run the new unit test: npm run test:php -- --filter test_edit_image_wp_slash_with_object_cast
Run all attachment controller tests: npm run test:php -- --filter WP_Test_REST_Attachments_Controller

cc @justlevine

Trac ticket: https://core.trac.wordpress.org/ticket/64149

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[github-actions]

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[github-actions]

The following accounts have interacted with this PR and/or linked issues. I will continue to update these lists as activity occurs. You can also manually ask me to refresh this list by adding the props-bot label.

Core Committers: Use this line as a base for the props when committing in SVN:

Props ramonopoly, westonruter, mukesh27, justlevine.

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[westonruter]

Good catch. This is something else that would have been caught by static analysis. PHPStan would have blocked it, and even PhpStorm complains:

[justlevine]

This is something else that would have been caught by static analysis. PHPStan would have blocked it,

@westonruter not hypothetical. it was caught by PHPstan , showed up when I was rebasing #7619 on trunk 🚀

[ramonjd]

Good catch. This is something else that would have been caught by static analysis. PHPStan would have blocked it, and even PhpStorm complains:

Thanks @westonruter and @justlevine - I need to double check my local set up.

[ramonjd]

Committed in r61065