Summary (*)

There is an issue with types in \Magento\GroupedProduct\Model\Product\Type\Grouped class, in method _prepareProduct. A variable can be set as false, and is then used in a foreach.

.CRITICAL: Exception: Warning: foreach() argument must be of type array|object, bool given in /var/www/html/vendor/magento/module-grouped-product/Model/Product/Type/Grouped.php on line 391 

Examples (*)

$associatedProducts = !$isStrictProcessMode || !empty($productsInfo)
            ? $this->getAssociatedProducts($product)
            : false;

        foreach ($associatedProducts as $subProduct) {

Proposed solution

$associatedProducts = !$isStrictProcessMode || !empty($productsInfo)
            ? $this->getAssociatedProducts($product)
            : [];

        foreach ($associatedProducts as $subProduct) {

Please provide Severity assessment for the Issue as Reporter. This information will help during Confirmation and Issue triage processes.

• Severity: S0 - Affects critical data or functionality and leaves users with no workaround.
• Severity: S1 - Affects critical data or functionality and forces users to employ a workaround.
• Severity: S2 - Affects non-critical data or functionality and forces users to employ a workaround.
• Severity: S3 - Affects non-critical data or functionality and does not force users to employ a workaround.
• Severity: S4 - Affects aesthetics, professional look and feel, “quality” or “usability”.