laminas-form is a package for validating and displaying simple and complex forms. When rendering validation error messages via the `formElementErrors()` view helper shipped with laminas-form, many messages will contain the submitted value. However, in laminas-form prior to version 3.1.1, the value was not being escaped for HTML contexts, which could potentially lead to a reflected cross-site scripting attack. Versions 3.1.1 and above contain a patch to mitigate the vulnerability. A workaround is available. One may manually place code at the top of a view script where one calls the `formElementErrors()` view helper. More information about this workaround is available on the GitHub Security Advisory.

Affected: Packagist: laminas/laminas-form

### Impact

When rendering validation error messages via the `formElementErrors()` view helper shipped with laminas-form, many messages will contain the submitted value. However, in vulnerable versions of laminas-form, the value was not being escaped for HTML contexts, which can potentially lead to a Reflected Cross-Site Scripting (XSS) attack.

### Patches

The following versions were issued to mitigate the vulnerability:

- 2.17.1 - 3.0.2 - 3.1.1

### Workarounds

At the top of a view script where you call the `formElementErrors()` view helper, place the following code:

```php use Laminas\Form\ElementInterface; use Laminas\View\PhpRenderer;

$escapeMessages = function (ElementInterface $formOrElement, PhpRenderer $renderer): void { $messages = $element->getMessages(); if (! $messages) { return; }

$escaped = []; array_walk_recursive( $messages, static function (string $item) use (&$escaped, $renderer): void { $escaped[] = $renderer->escapeHtml($item); } };

$element->setMessages($escaped); }; ```

Before calling `formElementErrors()` with a form, fieldset, or element, call the above closure as follows

```php // Usage with a form // $this is the view renderer $escapeMessages($form, $this);

// Usage with a fieldset // $this is the view renderer $escapeMessages($fieldset, $this);

// Usage with a form element // $this is the view renderer $escapeMessages($element, $this); ```

### For more information…