diff --git a/CHANGELOG.md b/CHANGELOG.md
index 5babb09b9..fb744b44d 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -9,6 +9,7 @@
     * Added `route` and `request` to `onPagesInitialized` event
     * Improved page cloning, added method `Page::initialize()`
     * Improved `FlexObject::getChanges()`: return changed lists and arrays as whole instead of just changed keys/values
+    * Improved form validation JSON responses to contain list of failed fields with their error messages
 3. [](#bugfix)
     * Fixed path traversal vulnerability when using `bin/grav server`
     * Fixed unescaped error messages in JSON error responses
diff --git a/system/src/Grav/Common/Data/ValidationException.php b/system/src/Grav/Common/Data/ValidationException.php
index 2d94ab816..be6a674d7 100644
--- a/system/src/Grav/Common/Data/ValidationException.php
+++ b/system/src/Grav/Common/Data/ValidationException.php
@@ -10,16 +10,18 @@
 namespace Grav\Common\Data;
 
 use Grav\Common\Grav;
+use JsonSerializable;
 use RuntimeException;
 
 /**
  * Class ValidationException
  * @package Grav\Common\Data
  */
-class ValidationException extends RuntimeException
+class ValidationException extends RuntimeException implements JsonSerializable
 {
     /** @var array */
     protected $messages = [];
+    protected $escape = true;
 
     /**
      * @param array $messages
@@ -32,21 +34,34 @@ class ValidationException extends RuntimeException
         $language = Grav::instance()['language'];
         $this->message = $language->translate('GRAV.FORM.VALIDATION_FAIL', null, true) . ' ' . $this->message;
 
-        foreach ($messages as $variable => &$list) {
+        foreach ($messages as $list) {
             $list = array_unique($list);
             foreach ($list as $message) {
-                $this->message .= "<br/>$message";
+                $this->message .= '<br/>' . htmlspecialchars($message, ENT_QUOTES | ENT_HTML5, 'UTF-8');
             }
         }
 
         return $this;
     }
 
+    public function setSimpleMessage(bool $escape = true): void
+    {
+        $first = reset($this->messages);
+        $message = reset($first);
+
+        $this->message = $escape ? htmlspecialchars($message, ENT_QUOTES | ENT_HTML5, 'UTF-8') : $message;
+    }
+
     /**
      * @return array
      */
-    public function getMessages()
+    public function getMessages(): array
     {
         return $this->messages;
     }
+
+    public function jsonSerialize(): array
+    {
+        return ['validation' => $this->messages];
+    }
 }
diff --git a/system/src/Grav/Framework/Controller/Traits/ControllerResponseTrait.php b/system/src/Grav/Framework/Controller/Traits/ControllerResponseTrait.php
index 5b4863573..afa08aa42 100644
--- a/system/src/Grav/Framework/Controller/Traits/ControllerResponseTrait.php
+++ b/system/src/Grav/Framework/Controller/Traits/ControllerResponseTrait.php
@@ -19,6 +19,7 @@ use Grav\Common\Utils;
 use Grav\Framework\Psr7\Response;
 use Grav\Framework\RequestHandler\Exception\RequestException;
 use Grav\Framework\Route\Route;
+use JsonSerializable;
 use Psr\Http\Message\ResponseInterface;
 use Psr\Http\Message\ServerRequestInterface;
 use Psr\Http\Message\StreamInterface;
@@ -209,6 +210,9 @@ trait ControllerResponseTrait
         } else {
             $message = htmlspecialchars($e->getMessage(), ENT_QUOTES | ENT_HTML5, 'UTF-8');
         }
+
+        $extra = $e instanceof JsonSerializable ? $e->jsonSerialize() : [];
+
         $response = [
             'code' => $code,
             'status' => 'error',
@@ -216,7 +220,7 @@ trait ControllerResponseTrait
             'error' => [
                 'code' => $code,
                 'message' => $message
-            ]
+            ] + $extra
         ];
 
         /** @var Debugger $debugger */
diff --git a/system/src/Grav/Framework/RequestHandler/Middlewares/Exceptions.php b/system/src/Grav/Framework/RequestHandler/Middlewares/Exceptions.php
index e09f1b257..9eadf72e3 100644
--- a/system/src/Grav/Framework/RequestHandler/Middlewares/Exceptions.php
+++ b/system/src/Grav/Framework/RequestHandler/Middlewares/Exceptions.php
@@ -16,6 +16,7 @@ use Grav\Common\Debugger;
 use Grav\Common\Grav;
 use Grav\Framework\Psr7\Response;
 use JsonException;
+use JsonSerializable;
 use Psr\Http\Message\ResponseInterface;
 use Psr\Http\Message\ServerRequestInterface;
 use Psr\Http\Server\MiddlewareInterface;
@@ -46,6 +47,9 @@ class Exceptions implements MiddlewareInterface
             } else {
                 $message = htmlspecialchars($exception->getMessage(), ENT_QUOTES | ENT_HTML5, 'UTF-8');
             }
+
+            $extra = $exception instanceof JsonSerializable ? $exception->jsonSerialize() : [];
+
             $response = [
                 'code' => $code,
                 'status' => 'error',
@@ -53,7 +57,7 @@ class Exceptions implements MiddlewareInterface
                 'error' => [
                     'code' => $code,
                     'message' => $message,
-                ]
+                ] + $extra
             ];
 
             /** @var Debugger $debugger */