diff --git a/packages/node_modules/@node-red/editor-api/lib/editor/locales.js b/packages/node_modules/@node-red/editor-api/lib/editor/locales.js
index a7f300cd3..ebe3e3281 100644
--- a/packages/node_modules/@node-red/editor-api/lib/editor/locales.js
+++ b/packages/node_modules/@node-red/editor-api/lib/editor/locales.js
@@ -39,9 +39,12 @@ module.exports = {
     },
     get: function(req,res) {
         var namespace = req.params[0];
-        var lngs = req.query.lng;
         namespace = namespace.replace(/\.json$/,"");
         var lang = req.query.lng || i18n.defaultLang; //apiUtil.determineLangFromHeaders(req.acceptsLanguages() || []);
+        if (/[^a-z\-]/i.test(lang)) {
+            res.json({});
+            return;
+        }
         var prevLang = i18n.i.language;
         // Trigger a load from disk of the language if it is not the default
         i18n.i.changeLanguage(lang, function(){
diff --git a/packages/node_modules/@node-red/runtime/lib/api/nodes.js b/packages/node_modules/@node-red/runtime/lib/api/nodes.js
index a06cbed96..aa5eca100 100644
--- a/packages/node_modules/@node-red/runtime/lib/api/nodes.js
+++ b/packages/node_modules/@node-red/runtime/lib/api/nodes.js
@@ -99,6 +99,10 @@ var api = module.exports = {
         return new Promise(function(resolve,reject) {
             var id = opts.id;
             var lang = opts.lang;
+            if (/[^a-z\-]/i.test(opts.lang)) {
+                reject(new Error("Invalid language: "+opts.lang));
+                return
+            }
             var result = runtime.nodes.getNodeConfig(id,lang);
             if (result) {
                 runtime.log.audit({event: "nodes.config.get",id:id}, opts.req);
@@ -124,6 +128,10 @@ var api = module.exports = {
     getNodeConfigs: function(opts) {
         return new Promise(function(resolve,reject) {
             runtime.log.audit({event: "nodes.configs.get"}, opts.req);
+            if (/[^a-z\-]/i.test(opts.lang)) {
+                reject(new Error("Invalid language: "+opts.lang));
+                return
+            }
             return resolve(runtime.nodes.getNodeConfigs(opts.lang));
         });
     },
@@ -398,6 +406,10 @@ var api = module.exports = {
             var namespace = opts.module;
             var lang = opts.lang;
             var prevLang = runtime.i18n.i.language;
+            if (/[^a-z\-]/i.test(lang)) {
+                reject(new Error("Invalid language: "+lang));
+                return
+            }
             // Trigger a load from disk of the language if it is not the default
             runtime.i18n.i.changeLanguage(lang, function(){
                 var nodeList = runtime.nodes.getNodeList();
@@ -427,6 +439,10 @@ var api = module.exports = {
         return new Promise(function(resolve,reject) {
             var namespace = opts.module;
             var lang = opts.lang;
+            if (/[^a-z\-]/i.test(lang)) {
+                reject(new Error("Invalid language: "+lang));
+                return
+            }
             var prevLang = runtime.i18n.i.language;
             // Trigger a load from disk of the language if it is not the default
             runtime.i18n.i.changeLanguage(lang, function(){
diff --git a/packages/node_modules/@node-red/util/lib/i18n.js b/packages/node_modules/@node-red/util/lib/i18n.js
index d95f4bec6..5d5a18887 100644
--- a/packages/node_modules/@node-red/util/lib/i18n.js
+++ b/packages/node_modules/@node-red/util/lib/i18n.js
@@ -24,7 +24,7 @@ var i18n = require("i18next");
 
 var when = require("when");
 var path = require("path");
-var fs = require("fs");
+var fs = require("fs-extra");
 
 var defaultLang = "en-US";
 
@@ -82,36 +82,28 @@ function mergeCatalog(fallback,catalog) {
 }
 
 
-function readFile(lng, ns) {
-    return new Promise((resolve, reject) => {
-        if (resourceCache[ns] && resourceCache[ns][lng]) {
-            resolve(resourceCache[ns][lng]);
-        } else if (resourceMap[ns]) {
-            var file = path.join(resourceMap[ns].basedir, lng, resourceMap[ns].file);
-            fs.readFile(file, "utf8", function (err, content) {
-                if (err) {
-                    reject(err);
-                } else {
-                    try {
-                        resourceCache[ns] = resourceCache[ns] || {};
-                        resourceCache[ns][lng] = JSON.parse(content.replace(/^\uFEFF/, ''));
-                        var baseLng = lng.split('-')[0];
-                        if (baseLng !== lng && resourceCache[ns][baseLng]) {
-                            mergeCatalog(resourceCache[ns][baseLng], resourceCache[ns][lng]);
-                        }
-                        if (lng !== defaultLang) {
-                            mergeCatalog(resourceCache[ns][defaultLang], resourceCache[ns][lng]);
-                        }
-                        resolve(resourceCache[ns][lng]);
-                    } catch (e) {
-                        reject(e);
-                    }
-                }
-            });
-        } else {
-            reject(new Error("Unrecognised namespace"));
+async function readFile(lng, ns) {
+    if (/[^a-z\-]/i.test(lng)) {
+        throw new Error("Invalid language: "+lng)
+    }
+    if (resourceCache[ns] && resourceCache[ns][lng]) {
+        return resourceCache[ns][lng];
+    } else if (resourceMap[ns]) {
+        const file = path.join(resourceMap[ns].basedir, lng, resourceMap[ns].file);
+        const content = await fs.readFile(file, "utf8");
+        resourceCache[ns] = resourceCache[ns] || {};
+        resourceCache[ns][lng] = JSON.parse(content.replace(/^\uFEFF/, ''));
+        var baseLng = lng.split('-')[0];
+        if (baseLng !== lng && resourceCache[ns][baseLng]) {
+            mergeCatalog(resourceCache[ns][baseLng], resourceCache[ns][lng]);
         }
-    });
+        if (lng !== defaultLang) {
+            mergeCatalog(resourceCache[ns][defaultLang], resourceCache[ns][lng]);
+        }
+        return resourceCache[ns][lng];
+    } else {
+        throw new Error("Unrecognised namespace");
+    }
 }
 
 var MessageFileLoader = {
@@ -182,6 +174,10 @@ function init() {
 function getCatalog(namespace,lang) {
     var result = null;
     lang = lang || defaultLang;
+    if (/[^a-z\-]/i.test(lang)) {
+        throw new Error("Invalid language: "+lng)
+    }
+
     if (resourceCache.hasOwnProperty(namespace)) {
         result = resourceCache[namespace][lang];
         if (!result) {