diff --git a/Libraries/LibJS/Runtime/JSONObject.cpp b/Libraries/LibJS/Runtime/JSONObject.cpp
index 064087f65a8..373d158005d 100644
--- a/Libraries/LibJS/Runtime/JSONObject.cpp
+++ b/Libraries/LibJS/Runtime/JSONObject.cpp
@@ -719,7 +719,10 @@ static ThrowCompletionOr<Value> parse_simdjson_value(VM& vm, simdjson::ondemand:
         return parse_simdjson_array(vm, value);
     case simdjson::ondemand::json_type::object:
         return parse_simdjson_object(vm, value);
+    case simdjson::ondemand::json_type::unknown:
+        return vm.throw_completion<SyntaxError>(ErrorType::JsonMalformed);
     }
+
     VERIFY_NOT_REACHED();
 }
 
@@ -760,7 +763,10 @@ static ThrowCompletionOr<Value> parse_simdjson_document(VM& vm, simdjson::ondema
         return parse_simdjson_array(vm, document);
     case simdjson::ondemand::json_type::object:
         return parse_simdjson_object(vm, document);
+    case simdjson::ondemand::json_type::unknown:
+        return vm.throw_completion<SyntaxError>(ErrorType::JsonMalformed);
     }
+
     VERIFY_NOT_REACHED();
 }
 
@@ -861,7 +867,7 @@ JS_DEFINE_NATIVE_FUNCTION(JSONObject::raw_json)
         return vm.throw_completion<SyntaxError>(ErrorType::JsonMalformed);
 
     simdjson::ondemand::json_type type;
-    if (doc.type().get(type))
+    if (doc.type().get(type) || type == simdjson::ondemand::json_type::unknown)
         return vm.throw_completion<SyntaxError>(ErrorType::JsonMalformed);
 
     if (type == simdjson::ondemand::json_type::object || type == simdjson::ondemand::json_type::array)
diff --git a/Meta/CMake/flatpak/org.ladybird.Ladybird.json b/Meta/CMake/flatpak/org.ladybird.Ladybird.json
index 72515176f19..1532b5a6a60 100644
--- a/Meta/CMake/flatpak/org.ladybird.Ladybird.json
+++ b/Meta/CMake/flatpak/org.ladybird.Ladybird.json
@@ -36,7 +36,7 @@
         {
           "type": "git",
           "url": "https://github.com/simdjson/simdjson.git",
-          "tag": "v3.12.2"
+          "tag": "v4.2.4"
         }
       ],
       "config-opts": [
diff --git a/vcpkg.json b/vcpkg.json
index 50aa1068dad..580c2081449 100644
--- a/vcpkg.json
+++ b/vcpkg.json
@@ -1,5 +1,5 @@
 {
-  "builtin-baseline": "4f95fba7a7d1101bb8acdeb51e4609686449701e",
+  "builtin-baseline": "2fa7118fb2ce0c27ab73e08ab1991f4cb67af880",
   "dependencies": [
     {
       "name": "angle",
@@ -232,6 +232,10 @@
       "name": "curl",
       "version": "8.16.0#0"
     },
+    {
+      "name": "dav1d",
+      "version": "1.5.1#0"
+    },
     {
       "name": "dbus",
       "version": "1.16.2#2"
@@ -310,7 +314,7 @@
     },
     {
       "name": "simdjson",
-      "version": "3.13.0#0"
+      "version": "4.2.4#0"
     },
     {
       "name": "simdutf",