diff --git a/cleantalk.php b/cleantalk.php
index 5d8a47fab..e3a7c07e8 100644
--- a/cleantalk.php
+++ b/cleantalk.php
@@ -2754,6 +2754,43 @@ function apbct_cookies_test()
     return null;
 }
 
+/**
+ * Whether an API result is a transport/connection failure (not an invalid Access key).
+ *
+ * @param mixed $result API result array, error string, or errors['account_check'] bucket
+ * @return bool
+ */
+function apbct__is_connection_error_result($result)
+{
+    if ( is_array($result) ) {
+        if ( isset($result['error']) ) {
+            $result = $result['error'];
+        } else {
+            // State::errorAdd stores a list of error entries under the type key
+            $last = end($result);
+            if ( is_array($last) && isset($last['error']) ) {
+                $result = $last['error'];
+            } elseif ( is_string($last) ) {
+                $result = $last;
+            } else {
+                return false;
+            }
+        }
+    }
+
+    if ( ! is_string($result) || $result === '' ) {
+        return false;
+    }
+
+    $error = strtolower($result);
+
+    return strpos($error, 'connection_error') !== false
+        || strpos($error, 'json_decode_error') !== false
+        || strpos($error, 'curl error') !== false
+        || strpos($error, 'failed to connect') !== false
+        || strpos($error, 'operation timed out') !== false;
+}
+
 /**
  * Inner function - Account status check. Scheduled in 1800 seconds for default!
  * @param $api_key
@@ -2764,13 +2801,16 @@ function ct_account_status_check($api_key = null, $process_errors = true)
 {
     global $apbct;
 
-    $api_key = $api_key ?: $apbct->api_key;
-    $result  = API::methodNoticePaidTill(
+    $previous_key_is_ok = ! empty($apbct->data['key_is_ok']);
+    $api_key            = $api_key ?: $apbct->api_key;
+    $result             = API::methodNoticePaidTill(
         $api_key,
         preg_replace('/http[s]?:\/\//', '', get_option('home'), 1),
         ! is_main_site() && $apbct->white_label ? 'anti-spam-hosting' : 'antispam'
     );
 
+    $is_connection_error = ! empty($result['error']) && apbct__is_connection_error_result($result);
+
     if ( empty($result['error']) || ! empty($result['valid']) ) {
         // Notices
         $apbct->data['notice_show']         = TT::getArrayValueAsInt($result, 'show_notice', 0);
@@ -2865,6 +2905,11 @@ function ct_account_status_check($api_key = null, $process_errors = true)
     if ( ! empty($result['valid']) ) {
         $apbct->data['key_is_ok'] = true;
         $result                   = true;
+    } elseif ( $is_connection_error ) {
+        // Transport/SSL/timeout failures must not mark the Access key as invalid.
+        // @see https://app.doboard.com/1/task/54504
+        $apbct->data['key_is_ok'] = $previous_key_is_ok;
+        $result                   = false;
     } else {
         $apbct->data['key_is_ok'] = false;
         $result                   = false;
diff --git a/inc/apbct-sync-react.php b/inc/apbct-sync-react.php
index e93aa5e8a..a9f78ae0f 100644
--- a/inc/apbct-sync-react.php
+++ b/inc/apbct-sync-react.php
@@ -45,27 +45,33 @@ function apbct_react_access_key_check()
     $apbct->errorDeleteAll(true);
 
     $account_is_ok = (bool) ct_account_status_check($apbct->settings['apikey']);
+    $connection_error = ! empty($apbct->errors['account_check'])
+        && apbct__is_connection_error_result($apbct->errors['account_check']);
 
     if ( $account_is_ok ) {
         $apbct->data['key_is_ok'] = true;
         $apbct->errorDelete('key_invalid key_get', 'save');
+        $message = '';
+    } elseif ( $connection_error ) {
+        // Keep key status; surface the real transport error instead of "key invalid"
+        $last_error = end($apbct->errors['account_check']);
+        $message    = __('Error occurred while checking account status.', 'cleantalk-spam-protect');
+        if ( is_array($last_error) && isset($last_error['error']) ) {
+            $message = (string) $last_error['error'];
+        }
     } else {
         $apbct->data['key_is_ok'] = false;
         $apbct->errorAdd(
             'key_invalid',
             __('Testing failed. Please check the Access key.', 'cleantalk-spam-protect')
         );
+        $message = __('Testing failed. Please check the Access key.', 'cleantalk-spam-protect');
     }
 
     $apbct->data['key_changed'] = false;
     $apbct->saveData();
 
-    apbct_react_sync_json_response(
-        $account_is_ok,
-        $account_is_ok
-            ? ''
-            : __('Testing failed. Please check the Access key.', 'cleantalk-spam-protect')
-    );
+    apbct_react_sync_json_response($account_is_ok, $message);
 }
 
 function apbct_react_sfw_update()
diff --git a/inc/cleantalk-settings.php b/inc/cleantalk-settings.php
index 590ed3de9..89efaefeb 100644
--- a/inc/cleantalk-settings.php
+++ b/inc/cleantalk-settings.php
@@ -2714,9 +2714,6 @@ function apbct_settings__sync($direct_call = false)
     // Feedback with app_agent
     ct_send_feedback('0:' . APBCT_AGENT); // 0 - request_id, agent version.
 
-    // Key is good by default
-    $apbct->data['key_is_ok'] = true;
-
     // Checking account status
     $result = ct_account_status_check($apbct->settings['apikey']);
 
@@ -2740,8 +2737,11 @@ function apbct_settings__sync($direct_call = false)
 
         // Updating brief data for dashboard widget
         cleantalk_get_brief_data($apbct->settings['apikey']);
-        // Key is not valid
-    } else {
+        // Key is not valid — but only when the cloud explicitly rejected it (not on connection errors)
+    } elseif (
+        empty($apbct->errors['account_check']) ||
+        ! apbct__is_connection_error_result($apbct->errors['account_check'])
+    ) {
         $apbct->data['key_is_ok'] = false;
         $apbct->errorAdd(
             'key_invalid',
diff --git a/lib/Cleantalk/Antispam/Integrations/CleantalkExternalForms.php b/lib/Cleantalk/Antispam/Integrations/CleantalkExternalForms.php
index 6ef38e73f..279fb960b 100644
--- a/lib/Cleantalk/Antispam/Integrations/CleantalkExternalForms.php
+++ b/lib/Cleantalk/Antispam/Integrations/CleantalkExternalForms.php
@@ -4,6 +4,7 @@
 
 use Cleantalk\ApbctWP\Variables\Post;
 use Cleantalk\ApbctWP\Escape;
+use Cleantalk\ApbctWP\Validate;
 
 class CleantalkExternalForms extends IntegrationBase
 {
@@ -14,8 +15,15 @@ public function doPrepareActions($argument)
     {
         if ( empty($_POST)
             || !apbct_is_post()
-            || Post::get('cleantalk_hidden_method') === ''
-            || Post::get('cleantalk_hidden_action') === ''
+            || Post::getString('cleantalk_hidden_method') === ''
+            || Post::getString('cleantalk_hidden_action') === ''
+        ) {
+            return false;
+        }
+
+        // Reject non-http(s) actions early (e.g. javascript:/data:) before any output.
+        if ( ! $this->isAllowedExternalFormAction(Post::getString('cleantalk_hidden_action'))
+            || ! $this->isAllowedExternalFormMethod(Post::getString('cleantalk_hidden_method'))
         ) {
             return false;
         }
@@ -27,11 +35,27 @@ public function getDataForChecking($argument)
     {
         if ( ! empty($_POST)
             && apbct_is_post()
-            && Post::get('cleantalk_hidden_method') !== ''
-            && Post::get('cleantalk_hidden_action') !== ''
+            && Post::getString('cleantalk_hidden_method') !== ''
+            && Post::getString('cleantalk_hidden_action') !== ''
         ) {
-            $this->action = Escape::escHtml(Post::get('cleantalk_hidden_action'));
-            $this->method = Escape::escHtml(Post::get('cleantalk_hidden_method'));
+            $action = Post::getString('cleantalk_hidden_action');
+            $method = Post::getString('cleantalk_hidden_method');
+
+            if ( ! $this->isAllowedExternalFormAction($action)
+                || ! $this->isAllowedExternalFormMethod($method)
+            ) {
+                return null;
+            }
+
+            // Keep a sanitized raw URL; escape for HTML only when rendering the form.
+            // HTML escaping alone does not block javascript: URLs in action attributes.
+            $this->action = Escape::escUrlRaw($action);
+            $this->method = strtoupper($method);
+
+            if ( empty($this->action) ) {
+                return null;
+            }
+
             unset($_POST['cleantalk_hidden_action'], $_POST['cleantalk_hidden_method']);
 
             /**
@@ -111,6 +135,22 @@ private function constructFormInnerElements($arr, $recursive_key)
 
     private function constructOriginExternalForm($action, $method)
     {
+        if ( empty($action)
+            || empty($method)
+            || ! $this->isAllowedExternalFormAction($action)
+            || ! $this->isAllowedExternalFormMethod($method)
+        ) {
+            return '';
+        }
+
+        // Restrict protocols at output: only http/https are allowed in form action.
+        $action = esc_url($action, array('http', 'https'));
+        $method = Escape::escHtml(strtoupper($method));
+
+        if ( empty($action) ) {
+            return '';
+        }
+
         // HTML form template
         $form_template = '
         <html lang="">
@@ -153,4 +193,30 @@ private function constructOriginExternalForm($action, $method)
 
         return $form_template;
     }
+
+    /**
+     * External form action must be an absolute http/https URL.
+     * javascript:, data:, vbscript: and other schemes are rejected.
+     *
+     * @param mixed $action
+     *
+     * @return bool
+     */
+    private function isAllowedExternalFormAction($action)
+    {
+        return is_string($action) && Validate::isUrl($action);
+    }
+
+    /**
+     * HTML form method may only be GET or POST.
+     *
+     * @param mixed $method
+     *
+     * @return bool
+     */
+    private function isAllowedExternalFormMethod($method)
+    {
+        return is_string($method)
+            && in_array(strtolower($method), array('get', 'post'), true);
+    }
 }
diff --git a/lib/Cleantalk/Common/Validate.php b/lib/Cleantalk/Common/Validate.php
index 9fabba8f2..a58df60e5 100644
--- a/lib/Cleantalk/Common/Validate.php
+++ b/lib/Cleantalk/Common/Validate.php
@@ -82,8 +82,16 @@ public static function isValidFilePath($variable)
 
     public static function isUrl($url)
     {
-        return ( strpos($url, 'http://') !== false || strpos($url, 'https://') !== false ) &&
-               filter_var($url, FILTER_VALIDATE_URL);
+        if ( ! is_string($url) || $url === '' ) {
+            return false;
+        }
+
+        $scheme = strtolower((string) parse_url($url, PHP_URL_SCHEME));
+
+        // Allow only http/https. Checking the scheme prevents javascript:/data: bypasses
+        // that embed "http://" or "https://" in the rest of the string.
+        return in_array($scheme, array('http', 'https'), true) &&
+               (bool) filter_var($url, FILTER_VALIDATE_URL);
     }
 
     /**
diff --git a/tests/Antispam/IntegrationsByHook/TestCleantalkExternalForms.php b/tests/Antispam/IntegrationsByHook/TestCleantalkExternalForms.php
new file mode 100644
index 000000000..acd8743dc
--- /dev/null
+++ b/tests/Antispam/IntegrationsByHook/TestCleantalkExternalForms.php
@@ -0,0 +1,106 @@
+<?php
+
+use Cleantalk\ApbctWP\Variables\Post;
+use Cleantalk\ApbctWP\Variables\Server;
+use Cleantalk\Antispam\Integrations\CleantalkExternalForms;
+use PHPUnit\Framework\TestCase;
+
+class TestCleantalkExternalForms extends TestCase
+{
+    /**
+     * @var CleantalkExternalForms
+     */
+    private $integration;
+
+    /**
+     * @var array
+     */
+    private $post_global;
+
+    /**
+     * @var array
+     */
+    private $server_global;
+
+    protected function setUp(): void
+    {
+        $this->integration = new CleantalkExternalForms();
+        $this->post_global = $_POST;
+        $this->server_global = $_SERVER;
+        $_SERVER['REQUEST_METHOD'] = 'POST';
+        $this->resetVariableCaches();
+    }
+
+    protected function tearDown(): void
+    {
+        $_POST = $this->post_global;
+        $_SERVER = $this->server_global;
+        $this->resetVariableCaches();
+    }
+
+    private function resetVariableCaches()
+    {
+        Post::getInstance()->variables = [];
+        Server::getInstance()->variables = [];
+    }
+
+    public function testDoPrepareActionsRejectsJavascriptAction()
+    {
+        $_POST = array(
+            'cleantalk_hidden_method' => 'POST',
+            'cleantalk_hidden_action' => 'javascript:alert(String.fromCharCode(80,83,67,45,88,83,83));void 0',
+        );
+        $this->resetVariableCaches();
+
+        $this->assertFalse($this->integration->doPrepareActions(null));
+    }
+
+    public function testDoPrepareActionsRejectsJavascriptHttpsBypass()
+    {
+        $_POST = array(
+            'cleantalk_hidden_method' => 'POST',
+            'cleantalk_hidden_action' => 'javascript://https://evil.com%0aalert(1)',
+        );
+        $this->resetVariableCaches();
+
+        $this->assertFalse($this->integration->doPrepareActions(null));
+    }
+
+    public function testDoPrepareActionsRejectsDataUri()
+    {
+        $_POST = array(
+            'cleantalk_hidden_method' => 'POST',
+            'cleantalk_hidden_action' => 'data:text/html,<script>alert(1)</script>',
+        );
+        $this->resetVariableCaches();
+
+        $this->assertFalse($this->integration->doPrepareActions(null));
+    }
+
+    public function testDoPrepareActionsRejectsInvalidMethod()
+    {
+        $_POST = array(
+            'cleantalk_hidden_method' => 'PUT',
+            'cleantalk_hidden_action' => 'https://example.com/form',
+        );
+        $this->resetVariableCaches();
+
+        $this->assertFalse($this->integration->doPrepareActions(null));
+    }
+
+    public function testDoPrepareActionsAllowsHttpHttps()
+    {
+        $_POST = array(
+            'cleantalk_hidden_method' => 'POST',
+            'cleantalk_hidden_action' => 'https://example.com/form',
+        );
+        $this->resetVariableCaches();
+
+        $this->assertTrue($this->integration->doPrepareActions(null));
+
+        $_POST['cleantalk_hidden_action'] = 'http://45.137.81.184/';
+        $this->resetVariableCaches();
+
+        $this->assertTrue($this->integration->doPrepareActions(null));
+    }
+}
diff --git a/tests/ApbctWP/ValidateTest.php b/tests/ApbctWP/ValidateTest.php
index ce24b9745..54da7a004 100644
--- a/tests/ApbctWP/ValidateTest.php
+++ b/tests/ApbctWP/ValidateTest.php
@@ -19,5 +19,12 @@ public function testIsUrl()
         $this->assertFalse(\Cleantalk\ApbctWP\Validate::isUrl('https://cleantalk.org/some-path/with_parameter=😭'));
         $this->assertFalse(\Cleantalk\ApbctWP\Validate::isUrl('ftp://cleantalk.org'));
         $this->assertFalse(\Cleantalk\ApbctWP\Validate::isUrl('cleantalk.org'));
+        $this->assertFalse(\Cleantalk\ApbctWP\Validate::isUrl('javascript:alert(1)'));
+        $this->assertFalse(\Cleantalk\ApbctWP\Validate::isUrl('javascript:alert(String.fromCharCode(80,83,67,45,88,83,83));void 0'));
+        $this->assertFalse(\Cleantalk\ApbctWP\Validate::isUrl('javascript://https://evil.com%0aalert(1)'));
+        $this->assertFalse(\Cleantalk\ApbctWP\Validate::isUrl("javascript:alert('http://x')"));
+        $this->assertFalse(\Cleantalk\ApbctWP\Validate::isUrl('data:text/html,<script>alert(1)</script>'));
+        $this->assertFalse(\Cleantalk\ApbctWP\Validate::isUrl('vbscript:msgbox(1)'));
+        $this->assertTrue(\Cleantalk\ApbctWP\Validate::isUrl('http://45.137.81.184/'));
     }
 }
diff --git a/tests/Common/HelperTest.php b/tests/Common/HelperTest.php
index b240d0a97..65b17355e 100644
--- a/tests/Common/HelperTest.php
+++ b/tests/Common/HelperTest.php
@@ -12,9 +12,26 @@ public function test_http__multi_request_error() {
 	    $this->assertArrayHasKey( 'error', Helper::httpMultiRequest( array(array('https://google.com')) ) );
     }
 
+	/**
+	 * @group integration
+	 */
 	public function test_http__multi_request_success() {
     	$res = Helper::httpMultiRequest( array('https://google.com', 'https://apple.com') );
 		$this->assertIsArray( $res );
+
+		// Top-level error (e.g. CURL_NOT_INSTALLED) is an array of strings and would
+		// falsely pass assertContainsOnly('string') without this check.
+		if ( isset($res['error']) ) {
+			$this->markTestSkipped('Outbound HTTP multi-request not available in this environment');
+		}
+
+		// Per-URL failures come back as arrays (e.g. ['error' => '']).
+		foreach ( $res as $body ) {
+			if ( ! is_string($body) ) {
+				$this->markTestSkipped('Outbound HTTP multi-request not available in this environment');
+			}
+		}
+
 		$this->assertContainsOnly( 'string', $res );
 	}