Fix sandbox bypass in the "column" filter under SourcePolicyInterface

CHANGELOG

@@ -6,6 +6,7 @@
  * Restrict allowed classes in `Twig\Profiler\Profile::unserialize()` to prevent arbitrary class instantiation
  * Escape root profile name in `HtmlDumper`
  * Deprecate the `Twig\Sandbox\SourcePolicyInterface` interface with no replacement
+ * Fix sandbox bypass in the "column" filter when sandboxing is enabled via `SourcePolicyInterface`
 
 # 3.26.0 (2026-05-20)
 

src/Extension/CoreExtension.php

@@ -1960,12 +1960,15 @@ final class CoreExtension extends AbstractExtension
         }
 
         if ($isSandboxed) {
-            $sandbox = $env->getExtension(SandboxExtension::class);
+            // The sandbox might be enabled via a SourcePolicyInterface, in which case the SandboxExtension
+            // would not consider the sandbox active without the current Source: $isSandboxed is already
+            // computed against the call-site source, so check the policy directly to honor that decision.
+            $policy = $env->getExtension(SandboxExtension::class)->getSecurityPolicy();
             foreach ($array as $item) {
                 if (\is_object($item)) {
-                    $sandbox->checkPropertyAllowed($item, (string) $name);
+                    $policy->checkPropertyAllowed($item, (string) $name);
                     if (null !== $index) {
-                        $sandbox->checkPropertyAllowed($item, (string) $index);
+                        $policy->checkPropertyAllowed($item, (string) $index);
                     }
                 }
             }

tests/Extension/SandboxTest.php

@@ -1173,6 +1173,84 @@ EOF
         $this->assertSame('bar', $twig->load('index')->render($params));
     }
 
+    public function testSourcePolicySandboxBlocksColumnFilterOnDisallowedProperty()
+    {
+        $sourcePolicy = new class implements SourcePolicyInterface {
+            public function enableSandbox(Source $source): bool
+            {
+                return true;
+            }
+        };
+
+        $params = ['obj' => new ColumnObject()];
+        $twig = $this->getEnvironment(false, [], ['index' => "{{ [obj]|column('bar')|first }}"], [], ['column', 'first'], [], [], [], $sourcePolicy);
+
+        try {
+            $twig->load('index')->render($params);
+            $this->fail('Sandbox should reject the "column" filter when the requested property is not in allowedProperties (SourcePolicyInterface).');
+        } catch (SecurityNotAllowedPropertyError $e) {
+            $this->assertSame('Twig\Tests\Extension\ColumnObject', $e->getClassName());
+            $this->assertSame('bar', $e->getPropertyName());
+        }
+    }
+
+    public function testSourcePolicySandboxBlocksColumnFilterOnDisallowedIndex()
+    {
+        $sourcePolicy = new class implements SourcePolicyInterface {
+            public function enableSandbox(Source $source): bool
+            {
+                return true;
+            }
+        };
+
+        $params = ['obj' => new ColumnObject()];
+        $twig = $this->getEnvironment(false, [], ['index' => "{{ [obj]|column('bar', 'foo')|keys|first }}"], [], ['column', 'first', 'keys'], [], ['Twig\Tests\Extension\ColumnObject' => ['bar']], [], $sourcePolicy);
+
+        try {
+            $twig->load('index')->render($params);
+            $this->fail('Sandbox should reject the "column" filter when the index argument targets a disallowed property (SourcePolicyInterface).');
+        } catch (SecurityNotAllowedPropertyError $e) {
+            $this->assertSame('Twig\Tests\Extension\ColumnObject', $e->getClassName());
+            $this->assertSame('foo', $e->getPropertyName());
+        }
+    }
+
+    public function testSourcePolicySandboxAllowsColumnFilterOnAllowedProperty()
+    {
+        $sourcePolicy = new class implements SourcePolicyInterface {
+            public function enableSandbox(Source $source): bool
+            {
+                return true;
+            }
+        };
+
+        $params = ['obj' => new ColumnObject()];
+        $twig = $this->getEnvironment(false, [], ['index' => "{{ [obj]|column('bar')|first }}"], [], ['column', 'first'], [], ['Twig\Tests\Extension\ColumnObject' => ['bar']], [], $sourcePolicy);
+
+        $this->assertSame('bar', $twig->load('index')->render($params));
+    }
+
+    public function testSourcePolicySandboxBlocksColumnFilterOnMagicGetter()
+    {
+        $sourcePolicy = new class implements SourcePolicyInterface {
+            public function enableSandbox(Source $source): bool
+            {
+                return true;
+            }
+        };
+
+        $params = ['magic' => new MagicObject()];
+        $twig = $this->getEnvironment(false, [], ['index' => "{{ [magic]|column('anything')|first }}"], [], ['column', 'first'], [], [], [], $sourcePolicy);
+
+        try {
+            $twig->load('index')->render($params);
+            $this->fail('Sandbox should reject the "column" filter before invoking __get on a non-allowlisted property (SourcePolicyInterface).');
+        } catch (SecurityNotAllowedPropertyError $e) {
+            $this->assertSame('Twig\Tests\Extension\MagicObject', $e->getClassName());
+            $this->assertSame('anything', $e->getPropertyName());
+        }
+    }
+
     protected function getEnvironment($sandboxed, $options, $templates, $tags = [], $filters = [], $methods = [], $properties = [], $functions = [], $sourcePolicy = null, bool $strict = false)
     {
         $loader = new ArrayLoader($templates);