diff --git a/apps/files_sharing/lib/Controller/ShareAPIController.php b/apps/files_sharing/lib/Controller/ShareAPIController.php
index e33f93e8ce6c5..2bd535e319f4c 100644
--- a/apps/files_sharing/lib/Controller/ShareAPIController.php
+++ b/apps/files_sharing/lib/Controller/ShareAPIController.php
@@ -808,6 +808,10 @@ public function updateShare(
 			throw new OCSNotFoundException($this->l->t('Wrong share ID, share doesn\'t exist'));
 		}
 
+		if ($share->getShareOwner() !== $this->currentUser && $share->getSharedBy() !== $this->currentUser) {
+			throw new OCSForbiddenException('You are not allowed to edit incomming shares');
+		}
+
 		if ($permissions === null &&
 			$password === null &&
 			$sendPasswordByTalk === null &&