Getting error Uncaught exception 'TypeError' with message 'Cannot access offset of type string on string' in /var/www/wp-includes/media.php:2147

[umesh.nevase]

WordPress 6.1 and PHP8.
Getting this error on the page with the old caption shortcodes. if regex does not find 2nd offset. giving below error

Uncaught exception 'TypeError' with message 'Cannot access offset of type string on string' in /var/www/wp-includes/media.php:2147

[umesh.nevase]

The issue is coming if [caption] shortcode doesn't have any attributes. The issue is not with 2nd offset.

I've reinitialized $attr to an array.
The Fatal error is coming with PHP 8.0 and WordPress 6.1

Trac ticket: https://core.trac.wordpress.org/ticket/56996

[umesh.nevase]

On WordPress 6.1 the issue is coming on line number: 2198
Replying to umesh.nevase:

WordPress 6.1 and PHP8.
Getting this error on the page with the old caption shortcodes. if regex does not find 2nd offset. giving below error

Uncaught exception 'TypeError' with message 'Cannot access offset of type string on string' in /var/www/wp-includes/media.php:2147

On PHP 8, there is a fatal error for the [caption] shortcode when there are no attributes.

To replicate the issue, add the following code to the shortcode block:
[caption]<img class="alignnone" src="test.jpeg" width="2048" height="1091" />Test[/caption]

I suggest solving this issue by casting $attr to an array, as this is the same way that the function shortcode_atts prevents this issue, which is what other shortcodde callback functions call, like wp_video_shortcode.

Trac ticket: https://core.trac.wordpress.org/ticket/56996

[LinSoftware]

This issue appears to the be the same one as https://core.trac.wordpress.org/ticket/45929