diff --git a/package-lock.json b/package-lock.json
index 03dca5710d..3369245e72 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -14761,9 +14761,9 @@
       "integrity": "sha512-KEyanRIDHooo8KuBxY3CC019NbwHtxdsxzRJUfaGqcxMrvBPBkosN+RUxx1nZFI6yrErq3KTW8HI/qrNIxHe0g=="
     },
     "kareem": {
-      "version": "2.1.0",
-      "resolved": "https://registry.npmjs.org/kareem/-/kareem-2.1.0.tgz",
-      "integrity": "sha512-ycoMY1tVkcH1/NaxGn2erZaUC3CodmX7Fl6DUVXjN73+uecWYTaaldRkxNY3HeSKQnQTWnoxRKnZfVHcB8tIWg=="
+      "version": "2.3.0",
+      "resolved": "https://registry.npmjs.org/kareem/-/kareem-2.3.0.tgz",
+      "integrity": "sha512-6hHxsp9e6zQU8nXsP+02HGWXwTkOEw6IROhF2ZA28cYbUk4eJ6QbtZvdqZOdD9YPKghG3apk5eOCvs+tLl3lRg=="
     },
     "karma": {
       "version": "3.0.0",
@@ -16768,6 +16768,12 @@
         "readable-stream": "^2.0.1"
       }
     },
+    "memory-pager": {
+      "version": "1.1.0",
+      "resolved": "https://registry.npmjs.org/memory-pager/-/memory-pager-1.1.0.tgz",
+      "integrity": "sha512-Mf9OHV/Y7h6YWDxTzX/b4ZZ4oh9NSXblQL8dtPCOomOtZciEHxePR78+uHFLLlsk01A6jVHhHsQZZ/WcIPpnzg==",
+      "optional": true
+    },
     "memwatch-next": {
       "version": "0.3.0",
       "resolved": "https://registry.npmjs.org/memwatch-next/-/memwatch-next-0.3.0.tgz",
@@ -17233,46 +17239,58 @@
       }
     },
     "mongodb": {
-      "version": "3.0.8",
-      "resolved": "https://registry.npmjs.org/mongodb/-/mongodb-3.0.8.tgz",
-      "integrity": "sha512-mj7yIUyAr9xnO2ev8pcVJ9uX7gSum5LLs1qIFoWLxA5Il50+jcojKtaO1/TbexsScZ9Poz00Pc3b86GiSqJ7WA==",
+      "version": "3.1.6",
+      "resolved": "https://registry.npmjs.org/mongodb/-/mongodb-3.1.6.tgz",
+      "integrity": "sha512-E5QJuXQoMlT7KyCYqNNMfAkhfQD79AT4F8Xd+6x37OX+8BL17GyXyWvfm6wuyx4wnzCCPoCSLeMeUN2S7dU9yw==",
       "requires": {
-        "mongodb-core": "3.0.8"
+        "mongodb-core": "3.1.5",
+        "safe-buffer": "^5.1.2"
       }
     },
     "mongodb-core": {
-      "version": "3.0.8",
-      "resolved": "https://registry.npmjs.org/mongodb-core/-/mongodb-core-3.0.8.tgz",
-      "integrity": "sha512-dFxfhH9N7ohuQnINyIl6dqEF8sYOE0WKuymrFf3L3cipJNrx+S8rAbNOTwa00/fuJCjBMJNFsaA+R2N16//UIw==",
+      "version": "3.1.5",
+      "resolved": "https://registry.npmjs.org/mongodb-core/-/mongodb-core-3.1.5.tgz",
+      "integrity": "sha512-emT/tM4ZBinqd6RZok+EzDdtN4LjYJIckv71qQVOEFmvXgT5cperZegVmTgox/1cx4XQu6LJ5ZuIwipP/eKdQg==",
       "requires": {
-        "bson": "~1.0.4",
-        "require_optional": "^1.0.1"
+        "bson": "^1.1.0",
+        "require_optional": "^1.0.1",
+        "safe-buffer": "^5.1.2",
+        "saslprep": "^1.0.0"
+      },
+      "dependencies": {
+        "bson": {
+          "version": "1.1.0",
+          "resolved": "https://registry.npmjs.org/bson/-/bson-1.1.0.tgz",
+          "integrity": "sha512-9Aeai9TacfNtWXOYarkFJRW2CWo+dRon+fuLZYJmvLV3+MiUp0bEI6IAZfXEIg7/Pl/7IWlLaDnhzTsD81etQA=="
+        }
       }
     },
     "mongoose": {
-      "version": "5.1.3",
-      "resolved": "https://registry.npmjs.org/mongoose/-/mongoose-5.1.3.tgz",
-      "integrity": "sha512-v+hHI/NxJtcVPm2cY+/kJfTfkkXVCz/le0iVdnh3enGi+fClhoaztjTtXQMdzIzNc+M0R93KcARpzvPQq/cWKQ==",
+      "version": "5.3.4",
+      "resolved": "https://registry.npmjs.org/mongoose/-/mongoose-5.3.4.tgz",
+      "integrity": "sha512-DIUWOyYgZv2zGi/BoFEaFiaCVuDonnzGhW3cnc3JFjBScYn6z24tS2j3VB0dtMoX8FFjxmmMVnlmHPEIbV4PKA==",
       "requires": {
-        "async": "2.1.4",
+        "async": "2.6.1",
         "bson": "~1.0.5",
-        "kareem": "2.1.0",
+        "kareem": "2.3.0",
         "lodash.get": "4.4.2",
-        "mongodb": "3.0.8",
+        "mongodb": "3.1.6",
+        "mongodb-core": "3.1.5",
         "mongoose-legacy-pluralize": "1.0.2",
-        "mpath": "0.4.1",
-        "mquery": "3.0.0",
+        "mpath": "0.5.1",
+        "mquery": "3.2.0",
         "ms": "2.0.0",
         "regexp-clone": "0.0.1",
+        "safe-buffer": "5.1.2",
         "sliced": "1.0.1"
       },
       "dependencies": {
         "async": {
-          "version": "2.1.4",
-          "resolved": "https://registry.npmjs.org/async/-/async-2.1.4.tgz",
-          "integrity": "sha1-LSFgx3iAMuTdbL4lAvH5osj2zeQ=",
+          "version": "2.6.1",
+          "resolved": "https://registry.npmjs.org/async/-/async-2.6.1.tgz",
+          "integrity": "sha512-fNEiL2+AZt6AlAw/29Cr0UDe4sRAHCpEHh54WMz+Bb7QfNcFw4h3loofyJpLeQs4Yx7yuqu/2dLgM5hKOs6HlQ==",
           "requires": {
-            "lodash": "^4.14.0"
+            "lodash": "^4.17.10"
           }
         }
       }
@@ -17417,30 +17435,34 @@
       }
     },
     "mpath": {
-      "version": "0.4.1",
-      "resolved": "http://registry.npmjs.org/mpath/-/mpath-0.4.1.tgz",
-      "integrity": "sha512-NNY/MpBkALb9jJmjpBlIi6GRoLveLUM0pJzgbp9vY9F7IQEb/HREC/nxrixechcQwd1NevOhJnWWV8QQQRE+OA=="
+      "version": "0.5.1",
+      "resolved": "https://registry.npmjs.org/mpath/-/mpath-0.5.1.tgz",
+      "integrity": "sha512-H8OVQ+QEz82sch4wbODFOz+3YQ61FYz/z3eJ5pIdbMEaUzDqA268Wd+Vt4Paw9TJfvDgVKaayC0gBzMIw2jhsg=="
     },
     "mquery": {
-      "version": "3.0.0",
-      "resolved": "https://registry.npmjs.org/mquery/-/mquery-3.0.0.tgz",
-      "integrity": "sha512-WL1Lk8v4l8VFSSwN3yCzY9TXw+fKVYKn6f+w86TRzOLSE8k1yTgGaLBPUByJQi8VcLbOdnUneFV/y3Kv874pnQ==",
+      "version": "3.2.0",
+      "resolved": "https://registry.npmjs.org/mquery/-/mquery-3.2.0.tgz",
+      "integrity": "sha512-qPJcdK/yqcbQiKoemAt62Y0BAc0fTEKo1IThodBD+O5meQRJT/2HSe5QpBNwaa4CjskoGrYWsEyjkqgiE0qjhg==",
       "requires": {
-        "bluebird": "3.5.0",
-        "debug": "2.6.9",
+        "bluebird": "3.5.1",
+        "debug": "3.1.0",
         "regexp-clone": "0.0.1",
-        "sliced": "0.0.5"
+        "safe-buffer": "5.1.2",
+        "sliced": "1.0.1"
       },
       "dependencies": {
         "bluebird": {
-          "version": "3.5.0",
-          "resolved": "https://registry.npmjs.org/bluebird/-/bluebird-3.5.0.tgz",
-          "integrity": "sha1-eRQg1/VR7qKJdFOop3ZT+WYG1nw="
+          "version": "3.5.1",
+          "resolved": "https://registry.npmjs.org/bluebird/-/bluebird-3.5.1.tgz",
+          "integrity": "sha512-MKiLiV+I1AA596t9w1sQJ8jkiSr5+ZKi0WKrYGUn6d1Fx+Ij4tIj+m2WMQSGczs5jZVxV339chE8iwk6F64wjA=="
         },
-        "sliced": {
-          "version": "0.0.5",
-          "resolved": "https://registry.npmjs.org/sliced/-/sliced-0.0.5.tgz",
-          "integrity": "sha1-XtwETKTrb3gW1Qui/GPiXY/kcH8="
+        "debug": {
+          "version": "3.1.0",
+          "resolved": "https://registry.npmjs.org/debug/-/debug-3.1.0.tgz",
+          "integrity": "sha512-OX8XqP7/1a9cqkxYw2yXss15f26NKWBpDXQd0/uK/KPqdQhxbPa994hnzjcE2VqQpDslf55723cKPUOGSmMY3g==",
+          "requires": {
+            "ms": "2.0.0"
+          }
         }
       }
     },
@@ -23387,6 +23409,15 @@
       "integrity": "sha512-1HwIYD/8UlOtFS3QO3w7ey+SdSDFE4HRNLZoZRYVQefrOY3l17epswImeB1ijgJFQJodIaHcwkp3r/myBjFVbg==",
       "dev": true
     },
+    "saslprep": {
+      "version": "1.0.2",
+      "resolved": "https://registry.npmjs.org/saslprep/-/saslprep-1.0.2.tgz",
+      "integrity": "sha512-4cDsYuAjXssUSjxHKRe4DTZC0agDwsCqcMqtJAQPzC74nJ7LfAJflAtC1Zed5hMzEQKj82d3tuzqdGNRsLJ4Gw==",
+      "optional": true,
+      "requires": {
+        "sparse-bitfield": "^3.0.3"
+      }
+    },
     "sass-graph": {
       "version": "2.2.4",
       "resolved": "https://registry.npmjs.org/sass-graph/-/sass-graph-2.2.4.tgz",
@@ -24122,6 +24153,15 @@
       "resolved": "https://registry.npmjs.org/sparkles/-/sparkles-1.0.1.tgz",
       "integrity": "sha512-dSO0DDYUahUt/0/pD/Is3VIm5TGJjludZ0HVymmhYF6eNA53PVLhnUk0znSYbH8IYBuJdCE+1luR22jNLMaQdw=="
     },
+    "sparse-bitfield": {
+      "version": "3.0.3",
+      "resolved": "https://registry.npmjs.org/sparse-bitfield/-/sparse-bitfield-3.0.3.tgz",
+      "integrity": "sha1-/0rm5oZWBWuks+eSqzM004JzyhE=",
+      "optional": true,
+      "requires": {
+        "memory-pager": "^1.0.2"
+      }
+    },
     "spdx-correct": {
       "version": "3.0.0",
       "resolved": "https://registry.npmjs.org/spdx-correct/-/spdx-correct-3.0.0.tgz",
diff --git a/package.json b/package.json
index 6933691080..ce1b54b530 100644
--- a/package.json
+++ b/package.json
@@ -62,7 +62,7 @@
     "method-override": "^3.0.0",
     "moment": "^2.22.1",
     "moment-recur": "^1.0.7",
-    "mongoose": "^5.1.3",
+    "mongoose": "^5.3.4",
     "morgan": "^1.7.0",
     "nconf": "^0.10.0",
     "node-gcm": "^1.0.2",
diff --git a/website/server/libs/baseModel.js b/website/server/libs/baseModel.js
index bdac19931d..4ed6d0aad7 100644
--- a/website/server/libs/baseModel.js
+++ b/website/server/libs/baseModel.js
@@ -8,7 +8,7 @@ module.exports = function baseModel (schema, options = {}) {
       _id: {
         type: String,
         default: uuid,
-        validate: [validator.isUUID, 'Invalid uuid.'],
+        validate: [v => validator.isUUID(v), 'Invalid uuid.'],
       },
     });
   }
diff --git a/website/server/models/challenge.js b/website/server/models/challenge.js
index bb18888928..d0f02c41c4 100644
--- a/website/server/models/challenge.js
+++ b/website/server/models/challenge.js
@@ -31,8 +31,8 @@ let schema = new Schema({
     todos: [{type: String, ref: 'Task'}],
     rewards: [{type: String, ref: 'Task'}],
   },
-  leader: {type: String, ref: 'User', validate: [validator.isUUID, 'Invalid uuid.'], required: true},
-  group: {type: String, ref: 'Group', validate: [validator.isUUID, 'Invalid uuid.'], required: true},
+  leader: {type: String, ref: 'User', validate: [v => validator.isUUID(v), 'Invalid uuid.'], required: true},
+  group: {type: String, ref: 'Group', validate: [v => validator.isUUID(v), 'Invalid uuid.'], required: true},
   memberCount: {type: Number, default: 0},
   prize: {type: Number, default: 0, min: 0},
   categories: [{
diff --git a/website/server/models/emailUnsubscription.js b/website/server/models/emailUnsubscription.js
index a0d1d0b7e6..4df2ab530b 100644
--- a/website/server/models/emailUnsubscription.js
+++ b/website/server/models/emailUnsubscription.js
@@ -9,7 +9,7 @@ export let schema = new mongoose.Schema({
     required: true,
     trim: true,
     lowercase: true,
-    validator: [validator.isEmail, 'Invalid email.'],
+    validator: [v => validator.isEmail(v), 'Invalid email.'],
   },
 }, {
   strict: true,
diff --git a/website/server/models/group.js b/website/server/models/group.js
index e2939278e3..95eb8dcffe 100644
--- a/website/server/models/group.js
+++ b/website/server/models/group.js
@@ -73,7 +73,7 @@ export let schema = new Schema({
   name: {type: String, required: true},
   summary: {type: String, maxlength: MAX_SUMMARY_SIZE_FOR_GUILDS},
   description: String,
-  leader: {type: String, ref: 'User', validate: [validator.isUUID, 'Invalid uuid.'], required: true},
+  leader: {type: String, ref: 'User', validate: [v => validator.isUUID(v), 'Invalid uuid.'], required: true},
   type: {type: String, enum: ['guild', 'party'], required: true},
   privacy: {type: String, enum: ['private', 'public'], default: 'private', required: true},
   chat: Array, // Used for backward compatibility, but messages aren't stored here
diff --git a/website/server/models/iapPurchaseReceipt.js b/website/server/models/iapPurchaseReceipt.js
index b29bd90425..a03fa69a5e 100644
--- a/website/server/models/iapPurchaseReceipt.js
+++ b/website/server/models/iapPurchaseReceipt.js
@@ -7,7 +7,7 @@ const Schema = mongoose.Schema;
 export let schema = new Schema({
   _id: {type: String, required: true}, // Use a custom string as _id
   consumed: {type: Boolean, default: false, required: true},
-  userId: {type: String, ref: 'User', required: true, validate: [validator.isUUID, 'Invalid uuid.']},
+  userId: {type: String, ref: 'User', required: true, validate: [v => validator.isUUID(v), 'Invalid uuid.']},
 }, {
   strict: true,
   minimize: false, // So empty objects are returned
diff --git a/website/server/models/subscriptionPlan.js b/website/server/models/subscriptionPlan.js
index e3994c8e06..86609cfa44 100644
--- a/website/server/models/subscriptionPlan.js
+++ b/website/server/models/subscriptionPlan.js
@@ -5,7 +5,7 @@ import validator from 'validator';
 export let schema = new mongoose.Schema({
   planId: String,
   subscriptionId: String,
-  owner: {type: String, ref: 'User', validate: [validator.isUUID, 'Invalid uuid.']},
+  owner: {type: String, ref: 'User', validate: [v => validator.isUUID(v), 'Invalid uuid.']},
   quantity: {type: Number, default: 1},
   paymentMethod: String, // enum: ['Paypal', 'Stripe', 'Gift', 'Amazon Payments', 'Google', '']}
   customerId: String, // Billing Agreement Id in case of Amazon Payments
diff --git a/website/server/models/tag.js b/website/server/models/tag.js
index 12940c4be9..659b50f1d7 100644
--- a/website/server/models/tag.js
+++ b/website/server/models/tag.js
@@ -9,7 +9,7 @@ export let schema = new Schema({
   id: {
     type: String,
     default: uuid,
-    validate: [validator.isUUID, 'Invalid uuid.'],
+    validate: [v => validator.isUUID(v), 'Invalid uuid.'],
     required: true,
   },
   name: {type: String, required: true},
diff --git a/website/server/models/task.js b/website/server/models/task.js
index 7614f46903..55dcf72499 100644
--- a/website/server/models/task.js
+++ b/website/server/models/task.js
@@ -76,7 +76,7 @@ export let TaskSchema = new Schema({
   },
   tags: [{
     type: String,
-    validate: [validator.isUUID, 'Invalid uuid.'],
+    validate: [v => validator.isUUID(v), 'Invalid uuid.'],
   }],
   value: {type: Number, default: 0, required: true}, // redness or cost for rewards Required because it must be settable (for rewards)
   priority: {
@@ -89,26 +89,26 @@ export let TaskSchema = new Schema({
     ],
   },
   attribute: {type: String, default: 'str', enum: ['str', 'con', 'int', 'per']},
-  userId: {type: String, ref: 'User', validate: [validator.isUUID, 'Invalid uuid.']}, // When not set it belongs to a challenge
+  userId: {type: String, ref: 'User', validate: [v => validator.isUUID(v), 'Invalid uuid.']}, // When not set it belongs to a challenge
 
   challenge: {
     shortName: {type: String},
-    id: {type: String, ref: 'Challenge', validate: [validator.isUUID, 'Invalid uuid.']}, // When set (and userId not set) it's the original task
-    taskId: {type: String, ref: 'Task', validate: [validator.isUUID, 'Invalid uuid.']}, // When not set but challenge.id defined it's the original task
+    id: {type: String, ref: 'Challenge', validate: [v => validator.isUUID(v), 'Invalid uuid.']}, // When set (and userId not set) it's the original task
+    taskId: {type: String, ref: 'Task', validate: [v => validator.isUUID(v), 'Invalid uuid.']}, // When not set but challenge.id defined it's the original task
     broken: {type: String, enum: ['CHALLENGE_DELETED', 'TASK_DELETED', 'UNSUBSCRIBED', 'CHALLENGE_CLOSED', 'CHALLENGE_TASK_NOT_FOUND']}, // CHALLENGE_TASK_NOT_FOUND comes from v3 migration
     winner: String, // user.profile.name of the winner
   },
 
   group: {
-    id: {type: String, ref: 'Group', validate: [validator.isUUID, 'Invalid uuid.']},
+    id: {type: String, ref: 'Group', validate: [v => validator.isUUID(v), 'Invalid uuid.']},
     broken: {type: String, enum: ['GROUP_DELETED', 'TASK_DELETED', 'UNSUBSCRIBED']},
-    assignedUsers: [{type: String, ref: 'User', validate: [validator.isUUID, 'Invalid uuid.']}],
-    taskId: {type: String, ref: 'Task', validate: [validator.isUUID, 'Invalid uuid.']},
+    assignedUsers: [{type: String, ref: 'User', validate: [v => validator.isUUID(v), 'Invalid uuid.']}],
+    taskId: {type: String, ref: 'Task', validate: [v => validator.isUUID(v), 'Invalid uuid.']},
     approval: {
       required: {type: Boolean, default: false},
       approved: {type: Boolean, default: false},
       dateApproved: {type: Date},
-      approvingUser: {type: String, ref: 'User', validate: [validator.isUUID, 'Invalid uuid.']},
+      approvingUser: {type: String, ref: 'User', validate: [v => validator.isUUID(v), 'Invalid uuid.']},
       requested: {type: Boolean, default: false},
       requestedDate: {type: Date},
     },
@@ -117,7 +117,7 @@ export let TaskSchema = new Schema({
 
   reminders: [{
     _id: false,
-    id: {type: String, validate: [validator.isUUID, 'Invalid uuid.'], default: shared.uuid, required: true},
+    id: {type: String, validate: [v => validator.isUUID(v), 'Invalid uuid.'], default: shared.uuid, required: true},
     startDate: {type: Date},
     time: {type: Date, required: true},
   }],
@@ -265,7 +265,7 @@ let dailyTodoSchema = () => {
       completed: {type: Boolean, default: false},
       text: {type: String, required: false, default: ''}, // required:false because it can be empty on creation
       _id: false,
-      id: {type: String, default: shared.uuid, required: true, validate: [validator.isUUID, 'Invalid uuid.']},
+      id: {type: String, default: shared.uuid, required: true, validate: [v => validator.isUUID(v), 'Invalid uuid.']},
       linkId: {type: String},
     }],
   };
diff --git a/website/server/models/user/schema.js b/website/server/models/user/schema.js
index d8517a753d..4ce701ecbe 100644
--- a/website/server/models/user/schema.js
+++ b/website/server/models/user/schema.js
@@ -35,7 +35,7 @@ let schema = new Schema({
       email: {
         type: String,
         validate: [{
-          validator: validator.isEmail,
+          validator: (v) => validator.isEmail(v),
           message: shared.i18n.t('invalidEmail'),
         }, {
           validator (email) {
@@ -374,7 +374,7 @@ let schema = new Schema({
     return {};
   }},
 
-  challenges: [{type: String, ref: 'Challenge', validate: [validator.isUUID, 'Invalid uuid.']}],
+  challenges: [{type: String, ref: 'Challenge', validate: [v => validator.isUUID(v), 'Invalid uuid.']}],
 
   invitations: {
     // Using an array without validation because otherwise mongoose treat this as a subdocument and applies _id by default
@@ -391,7 +391,7 @@ let schema = new Schema({
         type: String,
         ref: 'Group',
         required: true,
-        validate: [validator.isUUID, 'Invalid uuid.'],
+        validate: [v => validator.isUUID(v), 'Invalid uuid.'],
       },
       name: {
         type: String,
@@ -401,15 +401,15 @@ let schema = new Schema({
         type: String,
         ref: 'User',
         required: true,
-        validate: [validator.isUUID, 'Invalid uuid.'],
+        validate: [v => validator.isUUID(v), 'Invalid uuid.'],
       },
     }],
   },
 
-  guilds: [{type: String, ref: 'Group', validate: [validator.isUUID, 'Invalid uuid.']}],
+  guilds: [{type: String, ref: 'Group', validate: [v => validator.isUUID(v), 'Invalid uuid.']}],
 
   party: {
-    _id: {type: String, validate: [validator.isUUID, 'Invalid uuid.'], ref: 'Group'},
+    _id: {type: String, validate: [v => validator.isUUID(v), 'Invalid uuid.'], ref: 'Group'},
     order: {type: String, default: 'level'},
     orderAscending: {type: String, default: 'ascending'},
     quest: {
diff --git a/website/server/models/userNotification.js b/website/server/models/userNotification.js
index 15b4cec4d6..6ca205b03c 100644
--- a/website/server/models/userNotification.js
+++ b/website/server/models/userNotification.js
@@ -39,7 +39,7 @@ export let schema = new Schema({
   id: {
     type: String,
     default: uuid,
-    validate: [validator.isUUID, 'Invalid uuid.'],
+    validate: [v => validator.isUUID(v), 'Invalid uuid.'],
     // @TODO: Add these back once we figure out the issue with notifications
     // See Fix for https://github.com/HabitRPG/habitica/issues/9923
     // required: true,
diff --git a/website/server/models/webhook.js b/website/server/models/webhook.js
index 09dd6dd15c..3761166619 100644
--- a/website/server/models/webhook.js
+++ b/website/server/models/webhook.js
@@ -34,7 +34,7 @@ export let schema = new Schema({
   id: {
     type: String,
     required: true,
-    validate: [validator.isUUID, shared.i18n.t('invalidWebhookId')],
+    validate: [v => validator.isUUID(v), shared.i18n.t('invalidWebhookId')],
     default: uuid,
   },
   type: {