diff --git a/lib/taskana-core/src/main/java/pro/taskana/task/internal/AttachmentHandler.java b/lib/taskana-core/src/main/java/pro/taskana/task/internal/AttachmentHandler.java
index 903e57ad69..3a2ff88f27 100644
--- a/lib/taskana-core/src/main/java/pro/taskana/task/internal/AttachmentHandler.java
+++ b/lib/taskana-core/src/main/java/pro/taskana/task/internal/AttachmentHandler.java
@@ -45,7 +45,7 @@ void insertAndDeleteAttachmentsOnTaskUpdate(TaskImpl newTaskImpl, TaskImpl oldTa
     newTaskImpl.setAttachments(newAttachments);
 
     for (Attachment attachment : newAttachments) {
-      verifyAttachment((AttachmentImpl) attachment, newTaskImpl.getDomain());
+      verifyAttachment((AttachmentImpl) attachment, newTaskImpl.getDomain(), newTaskImpl.getId());
       initAttachment((AttachmentImpl) attachment, newTaskImpl);
     }
 
@@ -63,7 +63,7 @@ void insertNewAttachmentsOnTaskCreation(TaskImpl task)
     if (attachments != null) {
       for (Attachment attachment : attachments) {
         AttachmentImpl attachmentImpl = (AttachmentImpl) attachment;
-        verifyAttachment(attachmentImpl, task.getDomain());
+        verifyAttachment(attachmentImpl, task.getDomain(), task.getId());
         initAttachment(attachmentImpl, task);
 
         try {
@@ -176,7 +176,7 @@ private void initAttachment(AttachmentImpl attachment, Task newTask) {
     }
   }
 
-  private void verifyAttachment(AttachmentImpl attachment, String domain)
+  private void verifyAttachment(AttachmentImpl attachment, String domain, String taskId)
       throws InvalidArgumentException, ClassificationNotFoundException {
     ClassificationSummary classification = attachment.getClassificationSummary();
     if (classification == null) {
@@ -186,6 +186,11 @@ private void verifyAttachment(AttachmentImpl attachment, String domain)
       throw new InvalidArgumentException("ClassificationKey of Attachment must not be empty.");
     }
 
+    if (attachment.getTaskId() != null && !attachment.getTaskId().equals(taskId)) {
+      throw new InvalidArgumentException(
+              "An attachments' taskId must be empty or equal to the id of the task it belongs to");
+    }
+
     ObjectReferenceImpl.validate(attachment.getObjectReference(), "ObjectReference", "Attachment");
 
     classification =
diff --git a/rest/taskana-rest-spring/src/test/java/pro/taskana/task/rest/TaskControllerIntTest.java b/rest/taskana-rest-spring/src/test/java/pro/taskana/task/rest/TaskControllerIntTest.java
index 1093cc9dd5..00f2454111 100644
--- a/rest/taskana-rest-spring/src/test/java/pro/taskana/task/rest/TaskControllerIntTest.java
+++ b/rest/taskana-rest-spring/src/test/java/pro/taskana/task/rest/TaskControllerIntTest.java
@@ -37,6 +37,7 @@
 import org.springframework.http.HttpStatus;
 import org.springframework.http.ResponseEntity;
 import org.springframework.web.client.HttpStatusCodeException;
+import org.testcontainers.shaded.com.google.common.collect.Lists;
 import pro.taskana.TaskanaConfiguration;
 import pro.taskana.classification.rest.models.ClassificationSummaryRepresentationModel;
 import pro.taskana.common.internal.util.Pair;
@@ -45,6 +46,7 @@
 import pro.taskana.rest.test.TaskanaSpringBootTest;
 import pro.taskana.sampledata.SampleDataGenerator;
 import pro.taskana.task.api.TaskState;
+import pro.taskana.task.rest.models.AttachmentRepresentationModel;
 import pro.taskana.task.rest.models.IsReadRepresentationModel;
 import pro.taskana.task.rest.models.ObjectReferenceRepresentationModel;
 import pro.taskana.task.rest.models.TaskRepresentationModel;
@@ -139,6 +141,31 @@ private TaskRepresentationModel getTaskResourceSample() {
     return taskRepresentationModel;
   }
 
+  private ObjectReferenceRepresentationModel getObjectReferenceResourceSample() {
+    ObjectReferenceRepresentationModel objectReference = new ObjectReferenceRepresentationModel();
+    objectReference.setCompany("MyCompany1");
+    objectReference.setSystem("MySystem1");
+    objectReference.setSystemInstance("MyInstance1");
+    objectReference.setType("MyType1");
+    objectReference.setValue("00000001");
+    return objectReference;
+  }
+
+  private AttachmentRepresentationModel getAttachmentResourceSample() {
+    AttachmentRepresentationModel attachmentRepresentationModel =
+            new AttachmentRepresentationModel();
+    attachmentRepresentationModel.setAttachmentId("A11010");
+    attachmentRepresentationModel.setObjectReference(getObjectReferenceResourceSample());
+    ClassificationSummaryRepresentationModel classificationSummaryRepresentationModel =
+            new ClassificationSummaryRepresentationModel();
+    classificationSummaryRepresentationModel
+            .setClassificationId("CLI:100000000000000000000000000000000004");
+    classificationSummaryRepresentationModel.setKey("L11010");
+    attachmentRepresentationModel
+            .setClassificationSummary(classificationSummaryRepresentationModel);
+    return attachmentRepresentationModel;
+  }
+
   private ObjectReferenceRepresentationModel getSampleSecondaryObjectReference(String suffix) {
     ObjectReferenceRepresentationModel objectReference = new ObjectReferenceRepresentationModel();
     objectReference.setCompany("SecondaryCompany" + suffix);
@@ -1518,6 +1545,27 @@ void should_CreateAndDeleteTask() {
       assertThat(responseDeleted.getStatusCode()).isEqualTo(HttpStatus.NO_CONTENT);
     }
 
+    @Test
+    void should_CreateTaskWithError_When_SpecifyingAttachmentWrong() {
+      TaskRepresentationModel taskRepresentationModel = getTaskResourceSample();
+      AttachmentRepresentationModel attachmentRepresentationModel = getAttachmentResourceSample();
+      attachmentRepresentationModel.setTaskId(taskRepresentationModel.getTaskId() + "wrongId");
+      taskRepresentationModel.setAttachments(Lists.newArrayList(attachmentRepresentationModel));
+
+      String url = restHelper.toUrl(RestEndpoints.URL_TASKS);
+      HttpEntity<TaskRepresentationModel> auth =
+              new HttpEntity<>(
+                      taskRepresentationModel, RestHelper.generateHeadersForUser("teamlead-1"));
+
+      ThrowingCallable httpCall =
+              () -> TEMPLATE.exchange(url, HttpMethod.POST, auth, TASK_MODEL_TYPE);
+
+      assertThatThrownBy(httpCall)
+              .extracting(HttpStatusCodeException.class::cast)
+              .extracting(HttpStatusCodeException::getStatusCode)
+              .isEqualTo(HttpStatus.BAD_REQUEST);
+    }
+
     @Test
     void should_CreateAndDeleteTaskWithSecondaryObjectReferences_When_SpecifyingObjectReferences() {
       TaskRepresentationModel taskRepresentationModel = getTaskResourceSample();
@@ -1605,7 +1653,7 @@ void should_CreateTaskWithCorrectPriorityAndThenDeleteIt_When_NotSpecifyingManua
 
     /**
      * TSK-926: If Planned and Due Date is provided to create a task and not matching to service
-     * level throw an exception One is calculated by other other date +- service level.
+     * level throw an exception One is calculated by other date +- service level.
      */
     @Test
     void should_ThrowException_When_CreatingTaskWithPlannedAndDueDateNotMatchingServiceLevel() {
@@ -1741,6 +1789,36 @@ void should_ChangeValueOfModified_When_UpdatingTask() {
       assertThat(updatedTask).isNotNull();
       assertThat(originalTask.getModified()).isBefore(updatedTask.getModified());
     }
+
+    @Test
+    void should_ThrowError_When_UpdatingTaskWithBadAttachment() {
+      String url =
+              restHelper.toUrl(RestEndpoints.URL_TASKS_ID,
+                      "TKI:100000000000000000000000000000000000");
+      HttpEntity<Object> httpEntityWithoutBody =
+              new HttpEntity<>(RestHelper.generateHeadersForUser("teamlead-1"));
+
+      ResponseEntity<TaskRepresentationModel> responseGet =
+              TEMPLATE.exchange(url, HttpMethod.GET, httpEntityWithoutBody, TASK_MODEL_TYPE);
+
+      final TaskRepresentationModel originalTask = responseGet.getBody();
+
+      AttachmentRepresentationModel attachmentRepresentationModel = getAttachmentResourceSample();
+      attachmentRepresentationModel.setTaskId(originalTask.getTaskId() + "wrongId");
+      originalTask.setAttachments(Lists.newArrayList(attachmentRepresentationModel));
+
+
+      HttpEntity<TaskRepresentationModel> httpEntity =
+              new HttpEntity<>(originalTask, RestHelper.generateHeadersForUser("teamlead-1"));
+
+      ThrowingCallable httpCall =
+              () -> TEMPLATE.exchange(url, HttpMethod.PUT, httpEntity, TASK_MODEL_TYPE);
+
+      assertThatThrownBy(httpCall)
+              .extracting(HttpStatusCodeException.class::cast)
+              .extracting(HttpStatusCodeException::getStatusCode)
+              .isEqualTo(HttpStatus.BAD_REQUEST);
+    }
   }
 
   @Nested