fix: sanitize error output in server validation logs

Escape dynamic error messages with htmlspecialchars() before
concatenating into HTML strings stored in validation_logs. Add a
Purify-based mutator on Server model as defense-in-depth, with a
dedicated HTMLPurifier config that allows only safe structural tags.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

app/Actions/Server/ValidateServer.php

@@ -30,7 +30,8 @@ class ValidateServer
         ]);
         ['uptime' => $this->uptime, 'error' => $error] = $server->validateConnection();
         if (! $this->uptime) {
-            $this->error = 'Server is not reachable. Please validate your configuration and connection.<br>Check this <a target="_blank" class="text-black underline dark:text-white" href="https://coolify.io/docs/knowledge-base/server/openssh">documentation</a> for further help. <br><br><div class="text-error">Error: '.$error.'</div>';
+            $sanitizedError = htmlspecialchars($error ?? '', ENT_QUOTES, 'UTF-8');
+            $this->error = 'Server is not reachable. Please validate your configuration and connection.<br>Check this <a target="_blank" class="text-black underline dark:text-white" href="https://coolify.io/docs/knowledge-base/server/openssh">documentation</a> for further help. <br><br><div class="text-error">Error: '.$sanitizedError.'</div>';
             $server->update([
                 'validation_logs' => $this->error,
             ]);

app/Jobs/ValidateAndInstallServerJob.php

@@ -45,7 +45,8 @@ class ValidateAndInstallServerJob implements ShouldBeEncrypted, ShouldQueue
             // Validate connection
             ['uptime' => $uptime, 'error' => $error] = $this->server->validateConnection();
             if (! $uptime) {
-                $errorMessage = 'Server is not reachable. Please validate your configuration and connection.<br>Check this <a target="_blank" class="underline" href="https://coolify.io/docs/knowledge-base/server/openssh">documentation</a> for further help. <br><br>Error: '.$error;
+                $sanitizedError = htmlspecialchars($error ?? '', ENT_QUOTES, 'UTF-8');
+                $errorMessage = 'Server is not reachable. Please validate your configuration and connection.<br>Check this <a target="_blank" class="underline" href="https://coolify.io/docs/knowledge-base/server/openssh">documentation</a> for further help. <br><br>Error: '.$sanitizedError;
                 $this->server->update([
                     'validation_logs' => $errorMessage,
                     'is_validating' => false,
@@ -197,7 +198,7 @@ class ValidateAndInstallServerJob implements ShouldBeEncrypted, ShouldQueue
             ]);
 
             $this->server->update([
-                'validation_logs' => 'An error occurred during validation: '.$e->getMessage(),
+                'validation_logs' => 'An error occurred during validation: '.htmlspecialchars($e->getMessage(), ENT_QUOTES, 'UTF-8'),
                 'is_validating' => false,
             ]);
         }

app/Livewire/Server/PrivateKey/Show.php

@@ -63,7 +63,8 @@ class Show extends Component
                 $this->dispatch('success', 'Server is reachable.');
                 $this->dispatch('refreshServerShow');
             } else {
-                $this->dispatch('error', 'Server is not reachable.<br><br>Check this <a target="_blank" class="underline" href="https://coolify.io/docs/knowledge-base/server/openssh">documentation</a> for further help.<br><br>Error: '.$error);
+                $sanitizedError = htmlspecialchars($error ?? '', ENT_QUOTES, 'UTF-8');
+                $this->dispatch('error', 'Server is not reachable.<br><br>Check this <a target="_blank" class="underline" href="https://coolify.io/docs/knowledge-base/server/openssh">documentation</a> for further help.<br><br>Error: '.$sanitizedError);
 
                 return;
             }

app/Livewire/Server/ValidateAndInstall.php

@@ -89,7 +89,8 @@ class ValidateAndInstall extends Component
         $this->authorize('update', $this->server);
         ['uptime' => $this->uptime, 'error' => $error] = $this->server->validateConnection();
         if (! $this->uptime) {
-            $this->error = 'Server is not reachable. Please validate your configuration and connection.<br>Check this <a target="_blank" class="text-black underline dark:text-white" href="https://coolify.io/docs/knowledge-base/server/openssh">documentation</a> for further help. <br><br><div class="text-error">Error: '.$error.'</div>';
+            $sanitizedError = htmlspecialchars($error ?? '', ENT_QUOTES, 'UTF-8');
+            $this->error = 'Server is not reachable. Please validate your configuration and connection.<br>Check this <a target="_blank" class="text-black underline dark:text-white" href="https://coolify.io/docs/knowledge-base/server/openssh">documentation</a> for further help. <br><br><div class="text-error">Error: '.$sanitizedError.'</div>';
             $this->server->update([
                 'validation_logs' => $this->error,
             ]);

app/Models/Server.php

@@ -269,6 +269,13 @@ class Server extends BaseModel
 
     use HasSafeStringAttribute;
 
+    public function setValidationLogsAttribute($value): void
+    {
+        $this->attributes['validation_logs'] = $value !== null
+            ? \Stevebauman\Purify\Facades\Purify::config('validation_logs')->clean($value)
+            : null;
+    }
+
     public function type()
     {
         return 'server';