diff --git a/app/src/main/java/com/owncloud/android/ui/activity/ReceiveExternalFilesActivity.java b/app/src/main/java/com/owncloud/android/ui/activity/ReceiveExternalFilesActivity.java
index 99e68a196af5..48c4e10a6a00 100755
--- a/app/src/main/java/com/owncloud/android/ui/activity/ReceiveExternalFilesActivity.java
+++ b/app/src/main/java/com/owncloud/android/ui/activity/ReceiveExternalFilesActivity.java
@@ -1062,7 +1062,11 @@ public void uploadFiles() {
         preferences.setLastUploadPath(mUploadPath);
 
         if (resultCode == UriUploader.UriUploaderResultCode.OK) {
-            finish();
+            // While content:// URIs are copied to temporary files this Activity has to stay alive, otherwise its
+            // temporary read permission for those URIs is revoked. onTmpFilesCopied() finishes it once done.
+            if (!uploader.isTmpCopyInProgress()) {
+                finish();
+            }
         } else {
 
             int messageResTitle = R.string.uploader_error_title_file_cannot_be_uploaded;
diff --git a/app/src/main/java/com/owncloud/android/ui/asynctasks/CopyAndUploadContentUrisTask.kt b/app/src/main/java/com/owncloud/android/ui/asynctasks/CopyAndUploadContentUrisTask.kt
index 981f5842be42..5ac9503f6756 100644
--- a/app/src/main/java/com/owncloud/android/ui/asynctasks/CopyAndUploadContentUrisTask.kt
+++ b/app/src/main/java/com/owncloud/android/ui/asynctasks/CopyAndUploadContentUrisTask.kt
@@ -26,7 +26,6 @@ import kotlinx.coroutines.withContext
 import java.io.File
 import java.io.FileNotFoundException
 import java.io.FileOutputStream
-import java.io.InputStream
 import java.lang.ref.WeakReference
 
 @Suppress("TooGenericExceptionCaught")
@@ -50,20 +49,8 @@ class CopyAndUploadContentUrisTask(
         behaviour: Int,
         contentResolver: ContentResolver
     ) {
-        val inputStreams: List<InputStream?> = try {
-            sourceUris.map { contentResolver.openInputStream(it) }
-        } catch (e: FileNotFoundException) {
-            Log_OC.e(TAG, "Source file not found", e)
-            dispatchResult(ResultCode.LOCAL_FILE_NOT_FOUND)
-            return
-        } catch (e: SecurityException) {
-            Log_OC.e(TAG, "Insufficient permissions to open source URIs", e)
-            dispatchResult(ResultCode.FORBIDDEN)
-            return
-        }
-
         scope.launch(Dispatchers.IO) {
-            val result = performCopy(user, sourceUris, remotePaths, behaviour, contentResolver, inputStreams)
+            val result = performCopy(user, sourceUris, remotePaths, behaviour, contentResolver)
             withContext(Dispatchers.Main) {
                 dispatchResult(result)
             }
@@ -75,8 +62,7 @@ class CopyAndUploadContentUrisTask(
         sourceUris: Array<Uri>,
         remotePaths: Array<String>,
         behaviour: Int,
-        contentResolver: ContentResolver,
-        inputStreams: List<InputStream?>
+        contentResolver: ContentResolver
     ): ResultCode {
         val localPaths = arrayOfNulls<String>(sourceUris.size)
         val resolvedRemotePaths = arrayOfNulls<String>(sourceUris.size)
@@ -95,7 +81,7 @@ class CopyAndUploadContentUrisTask(
                 }
                 Log_OC.d(TAG, "Cache file creation result: ${cacheFile.createNewFile()}")
 
-                inputStreams[index]?.use { input ->
+                contentResolver.openInputStream(uri)?.use { input ->
                     FileOutputStream(currentTempPath).use { output ->
                         input.copyTo(output)
                     }
diff --git a/app/src/main/java/com/owncloud/android/ui/helpers/UriUploader.kt b/app/src/main/java/com/owncloud/android/ui/helpers/UriUploader.kt
index 7ff1d70cca16..42a63ea6d5f1 100644
--- a/app/src/main/java/com/owncloud/android/ui/helpers/UriUploader.kt
+++ b/app/src/main/java/com/owncloud/android/ui/helpers/UriUploader.kt
@@ -64,6 +64,16 @@ class UriUploader @JvmOverloads constructor(
         ERROR_SENSITIVE_PATH
     }
 
+    /**
+     * True when content:// URIs are being copied to temporary files in the background.
+     *
+     * The temporary read permission for those URIs belongs to the calling Activity and is revoked once that Activity is
+     * destroyed. Callers must therefore stay alive until [OnCopyTmpFilesTaskListener.onTmpFilesCopied] is invoked,
+     * otherwise opening the URIs fails with a SecurityException.
+     */
+    var isTmpCopyInProgress: Boolean = false
+        private set
+
     @Suppress("NestedBlockDepth")
     fun uploadUris(): UriUploaderResultCode {
         var code = UriUploaderResultCode.OK
@@ -165,6 +175,7 @@ class UriUploader @JvmOverloads constructor(
         val taskRetainerFragment =
             fm.findFragmentByTag(TaskRetainerFragment.FTAG_TASK_RETAINER_FRAGMENT) as TaskRetainerFragment?
         taskRetainerFragment?.setTask(copyTask)
+        isTmpCopyInProgress = true
         copyTask.execute(
             user,
             sourceUris,