diff --git a/functions/package.json b/functions/package.json
index 199e01e..abc9974 100644
--- a/functions/package.json
+++ b/functions/package.json
@@ -19,7 +19,7 @@
     "express": "^4.17.1",
     "firebase-admin": "^8.2.0",
     "firebase-functions": "^3.1.0",
-    "lodash": "^4.17.14"
+    "lodash": "^4.17.21"
   },
   "devDependencies": {
     "eslint": "^4.12.0",
diff --git a/functions/yarn.lock b/functions/yarn.lock
index 4a8e20f..187f025 100644
--- a/functions/yarn.lock
+++ b/functions/yarn.lock
@@ -1455,10 +1455,10 @@ lodash.once@^4.0.0:
   resolved "https://registry.yarnpkg.com/lodash.once/-/lodash.once-4.1.1.tgz#0dd3971213c7c56df880977d504c88fb471a97ac"
   integrity sha1-DdOXEhPHxW34gJd9UEyI+0cal6w=
 
-lodash@^4.17.14, lodash@^4.17.4, lodash@^4.3.0:
-  version "4.17.15"
-  resolved "https://registry.yarnpkg.com/lodash/-/lodash-4.17.15.tgz#b447f6670a0455bbfeedd11392eff330ea097548"
-  integrity sha512-8xOcRHvCjnocdS5cpwXQXVzmmh5e5+saE2QGoeQmbKmRS6J3VQppPOIt0MnmE+4xlZoumy0GPG0D0MVIQbNA1A==
+lodash@^4.17.14, lodash@^4.17.21, lodash@^4.17.4, lodash@^4.3.0:
+  version "4.17.21"
+  resolved "https://registry.yarnpkg.com/lodash/-/lodash-4.17.21.tgz#679591c564c3bffaae8454cf0b3df370c3d6911c"
+  integrity sha512-v2kDEe57lecTulaDIuNTPy3Ry4gLGJ6Z1O3vE1krgXZNrsQ+LFTGHVxVjcXPs17LhbZVGedAJv8XZ1tvj5FvSg==
 
 long@^4.0.0:
   version "4.0.0"