diff --git a/www/tape/BackupOverview.js b/www/tape/BackupOverview.js
index f8e9dfd7..8f092db0 100644
--- a/www/tape/BackupOverview.js
+++ b/www/tape/BackupOverview.js
@@ -116,7 +116,7 @@ Ext.define('PBS.TapeManagement.BackupOverview', {
 
 		Proxmox.Utils.setErrorMask(view, false);
 	    } catch (error) {
-		Proxmox.Utils.setErrorMask(view, error.toString());
+		Proxmox.Utils.setErrorMask(view, Ext.htmlEncode(error.toString()));
 	    }
 	},
 
diff --git a/www/tape/ChangerStatus.js b/www/tape/ChangerStatus.js
index e18af90e..53e40857 100644
--- a/www/tape/ChangerStatus.js
+++ b/www/tape/ChangerStatus.js
@@ -597,7 +597,8 @@ Ext.define('PBS.TapeManagement.ChangerStatus', {
 		if (!use_cache) {
 		    Proxmox.Utils.setErrorMask(view);
 		}
-		Proxmox.Utils.setErrorMask(me.lookup('content'), response.result.message.toString());
+		let msg = Ext.htmlEncode(response.result.message.toString());
+		Proxmox.Utils.setErrorMask(me.lookup('content'), msg);
 	    }
 
 	    me.scheduleReload(5000);