diff --git a/desktop/toolkit/qt6/qt6-declarative/files/9c6b2b78e9076f1c2676aa0c41573db9ca480654.diff b/desktop/toolkit/qt6/qt6-declarative/files/9c6b2b78e9076f1c2676aa0c41573db9ca480654.diff
new file mode 100644
index 0000000000..8f3618e894
--- /dev/null
+++ b/desktop/toolkit/qt6/qt6-declarative/files/9c6b2b78e9076f1c2676aa0c41573db9ca480654.diff
@@ -0,0 +1,226 @@
+diff --git a/src/qml/jsruntime/qv4lookup_p.h b/src/qml/jsruntime/qv4lookup_p.h
+index 083c3ec2df8..ef36bf67c50 100644
+--- a/src/qml/jsruntime/qv4lookup_p.h
++++ b/src/qml/jsruntime/qv4lookup_p.h
+@@ -159,6 +159,10 @@ struct Q_QML_EXPORT Lookup {
+             const QQmlPropertyData *propertyData;
+         } qobjectMethodLookup;
+         struct {
++            // NB: None of this is actually cache-able. The metaobject may change at any time.
++            //     We invalidate this data every time the lookup is invoked and thereby force a
++            //     re-initialization next time.
++
+             quintptr isConstant; // This is a bool, encoded as 0 or 1. Both values are ignored by gc
+             quintptr metaObject; // a (const QMetaObject* & 1) or nullptr
+             int coreIndex;
+diff --git a/src/qml/qml/qqml.cpp b/src/qml/qml/qqml.cpp
+index 4e3b4fcf1ee..3f0d9e332b1 100644
+--- a/src/qml/qml/qqml.cpp
++++ b/src/qml/qml/qqml.cpp
+@@ -1386,16 +1386,16 @@ struct FallbackPropertyQmlData
+ 
+ static FallbackPropertyQmlData findFallbackPropertyQmlData(QV4::Lookup *lookup, QObject *object)
+ {
++    // We've just initialized the lookup. So everything must be fine here.
++
+     QQmlData *qmlData = QQmlData::get(object);
+-    if (qmlData && qmlData->isQueuedForDeletion)
+-        return {qmlData, nullptr, PropertyResult::Deleted};
+ 
++    Q_ASSERT(!qmlData || !qmlData->isQueuedForDeletion);
+     Q_ASSERT(!QQmlData::wasDeleted(object));
+ 
+     const QMetaObject *metaObject
+             = reinterpret_cast<const QMetaObject *>(lookup->qobjectFallbackLookup.metaObject - 1);
+-    if (!metaObject || metaObject != object->metaObject())
+-        return {qmlData, nullptr, PropertyResult::NeedsInit};
++    Q_ASSERT(metaObject == object->metaObject());
+ 
+     return {qmlData, metaObject, PropertyResult::OK};
+ }
+@@ -2585,6 +2585,7 @@ bool AOTCompiledContext::loadScopeObjectPropertyLookup(uint index, void *target)
+         break;
+     case QV4::Lookup::Call::ContextGetterScopeObjectPropertyFallback:
+         result = loadFallbackProperty(lookup, qmlScopeObject, target, this);
++        lookup->call = QV4::Lookup::Call::ContextGetterGeneric;
+         break;
+     default:
+         return false;
+@@ -2616,6 +2617,7 @@ bool AOTCompiledContext::writeBackScopeObjectPropertyLookup(uint index, void *so
+         break;
+     case QV4::Lookup::Call::ContextGetterScopeObjectPropertyFallback:
+         result = writeBackFallbackProperty(lookup, qmlScopeObject, source);
++        lookup->call = QV4::Lookup::Call::ContextGetterGeneric;
+         break;
+     default:
+         return false;
+@@ -2816,6 +2818,7 @@ bool AOTCompiledContext::getObjectLookup(uint index, QObject *object, void *targ
+         result = lookup->asVariant
+                 ? loadFallbackAsVariant(lookup, object, target, this)
+                 : loadFallbackProperty(lookup, object, target, this);
++        lookup->call = QV4::Lookup::Call::GetterGeneric;
+         break;
+     default:
+         return false;
+@@ -2850,6 +2853,7 @@ bool AOTCompiledContext::writeBackObjectLookup(uint index, QObject *object, void
+         result = lookup->asVariant
+                 ? writeBackFallbackAsVariant(lookup, object, source)
+                 : writeBackFallbackProperty(lookup, object, source);
++        lookup->call = QV4::Lookup::Call::GetterGeneric;
+         break;
+     default:
+         return false;
+@@ -3010,6 +3014,7 @@ bool AOTCompiledContext::setObjectLookup(uint index, QObject *object, void *valu
+         result = lookup->asVariant
+                 ? storeFallbackAsVariant(engine->handle(), lookup, object, value)
+                 : storeFallbackProperty(lookup, object, value);
++        lookup->call = QV4::Lookup::Call::SetterGeneric;
+         break;
+     default:
+         return false;
+diff --git a/tests/auto/qml/qmlcppcodegen/data/CMakeLists.txt b/tests/auto/qml/qmlcppcodegen/data/CMakeLists.txt
+index 79e908c9674..67cdefa30d9 100644
+--- a/tests/auto/qml/qmlcppcodegen/data/CMakeLists.txt
++++ b/tests/auto/qml/qmlcppcodegen/data/CMakeLists.txt
+@@ -26,6 +26,7 @@ set(cpp_sources
+     multiforeign.h
+     objectwithmethod.h
+     person.cpp person.h
++    propertymap.h
+     qmlusing.h
+     recursiveObject.h
+     refuseWrite.h
+@@ -282,6 +283,7 @@ set(qml_files
+     popContextAfterRet.qml
+     prefixedMetaType.qml
+     pressAndHoldButton.qml
++    propertyMap.qml
+     qmlUsing.qml
+     qtbug113150.qml
+     qtfont.qml
+diff --git a/tests/auto/qml/qmlcppcodegen/data/propertyMap.qml b/tests/auto/qml/qmlcppcodegen/data/propertyMap.qml
+new file mode 100644
+index 00000000000..c00f3972e8a
+--- /dev/null
++++ b/tests/auto/qml/qmlcppcodegen/data/propertyMap.qml
+@@ -0,0 +1,6 @@
++pragma Strict
++import TestTypes
++
++WithPropertyMap {
++    objectName: map.foo
++}
+diff --git a/tests/auto/qml/qmlcppcodegen/data/propertymap.h b/tests/auto/qml/qmlcppcodegen/data/propertymap.h
+new file mode 100644
+index 00000000000..64d84c5c097
+--- /dev/null
++++ b/tests/auto/qml/qmlcppcodegen/data/propertymap.h
+@@ -0,0 +1,40 @@
++// Copyright (C) 2025 The Qt Company Ltd.
++// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR GPL-3.0-only
++
++#ifndef PROPERTYMAP_H
++#define PROPERTYMAP_H
++
++#include <QtCore/qobject.h>
++#include <QtQml/qqml.h>
++#include <QtQml/qqmlpropertymap.h>
++
++class WithPropertyMap : public QObject
++{
++    Q_OBJECT
++    QML_ELEMENT
++    Q_PROPERTY(QQmlPropertyMap *map READ map NOTIFY mapChanged)
++public:
++    WithPropertyMap(QObject *parent = nullptr)
++        : QObject(parent)
++        , m_map(new QQmlPropertyMap(this))
++    {
++    }
++
++    QQmlPropertyMap *map() const { return m_map; }
++
++    void setProperties(const QVariantHash &properties)
++    {
++        delete m_map;
++        m_map = new QQmlPropertyMap(this);
++        m_map->insert(properties);
++        emit mapChanged();
++    }
++
++signals:
++    void mapChanged();
++
++private:
++    QQmlPropertyMap *m_map = nullptr;
++};
++
++#endif // PROPERTYMAP_H
+diff --git a/tests/auto/qml/qmlcppcodegen/tst_qmlcppcodegen.cpp b/tests/auto/qml/qmlcppcodegen/tst_qmlcppcodegen.cpp
+index 70c50b457a9..a90e2a60505 100644
+--- a/tests/auto/qml/qmlcppcodegen/tst_qmlcppcodegen.cpp
++++ b/tests/auto/qml/qmlcppcodegen/tst_qmlcppcodegen.cpp
+@@ -10,6 +10,7 @@
+ #include <data/getOptionalLookup.h>
+ #include <data/listprovider.h>
+ #include <data/objectwithmethod.h>
++#include <data/propertymap.h>
+ #include <data/qmlusing.h>
+ #include <data/refuseWrite.h>
+ #include <data/resettable.h>
+@@ -237,6 +238,7 @@ private slots:
+     void parentProperty();
+     void popContextAfterRet();
+     void prefixedType();
++    void propertyMap();
+     void propertyOfParent();
+     void qmlUsing();
+     void qtfont();
+@@ -4908,6 +4910,47 @@ void tst_QmlCppCodegen::prefixedType()
+     QCOMPARE(o->property("countH").toInt(), 11);
+ }
+ 
++void tst_QmlCppCodegen::propertyMap()
++{
++    QQmlEngine engine;
++
++    const QUrl document(u"qrc:/qt/qml/TestTypes/propertyMap.qml"_s);
++    QQmlComponent c(&engine, document);
++    QVERIFY2(c.isReady(), qPrintable(c.errorString()));
++
++    QTest::ignoreMessage(
++            QtWarningMsg, qPrintable(
++                document.toString()
++                + u":5:5: QML WithPropertyMap: Unable to assign [undefined] to \"objectName\""));
++
++    QScopedPointer<QObject> o(c.create());
++    QVERIFY(o);
++
++    WithPropertyMap *w = qobject_cast<WithPropertyMap *>(o.data());
++    QVERIFY(w);
++
++    QVERIFY(w->objectName().isEmpty());
++
++    w->setProperties({
++        { u"foo"_s, u"aaa"_s },
++        { u"bar"_s, u"bbb"_s },
++    });
++
++    QCOMPARE(w->objectName(), u"aaa"_s);
++
++    w->setProperties({
++        { u"foo"_s, u"ccc"_s },
++    });
++
++    QCOMPARE(w->objectName(), u"ccc"_s);
++
++    w->setProperties({
++        { u"foo"_s, 24.25 },
++    });
++
++    QCOMPARE(w->objectName(), u"24.25"_s);
++}
++
+ void tst_QmlCppCodegen::propertyOfParent()
+ {
+     QQmlEngine engine;
diff --git a/desktop/toolkit/qt6/qt6-declarative/pspec.xml b/desktop/toolkit/qt6/qt6-declarative/pspec.xml
index b33e99e6d3..85dc352fd7 100755
--- a/desktop/toolkit/qt6/qt6-declarative/pspec.xml
+++ b/desktop/toolkit/qt6/qt6-declarative/pspec.xml
@@ -29,7 +29,7 @@
             <Dependency versionFrom="6.10.1">qt6-languageserver-devel</Dependency>
         </BuildDependencies>
         <Patches>
-<!--             <Patch level="1">CVE-2025-12385-qtdeclarative-6.9-0001.diff</Patch> -->
+            <Patch level="1">9c6b2b78e9076f1c2676aa0c41573db9ca480654.diff</Patch>
 <!--             <Patch level="1">CVE-2025-12385-qtdeclarative-6.9-0002.diff</Patch> -->
         </Patches>
     </Source>
@@ -74,7 +74,7 @@
                                 </Files>
                 </Package-->
     <History>
-        <Update release="20">
+        <Update release="21">
             <Date>2025-11-30</Date>
             <Version>6.10.1</Version>
             <Comment>Version bump.</Comment>