diff --git a/package-lock.json b/package-lock.json
index 785d896..3881b0a 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -822,12 +822,12 @@
         },
         "acorn": {
           "version": "2.7.0",
-          "resolved": "http://registry.npmjs.org/acorn/-/acorn-2.7.0.tgz",
+          "resolved": "https://registry.npmjs.org/acorn/-/acorn-2.7.0.tgz",
           "integrity": "sha1-q259nYhqrKiwhbwzEreaGYQz8Oc="
         },
         "acorn-globals": {
           "version": "1.0.9",
-          "resolved": "http://registry.npmjs.org/acorn-globals/-/acorn-globals-1.0.9.tgz",
+          "resolved": "https://registry.npmjs.org/acorn-globals/-/acorn-globals-1.0.9.tgz",
           "integrity": "sha1-VbtemGkVB7dFedBRNBMhfDgMVM8=",
           "requires": {
             "acorn": "^2.1.0"
@@ -851,7 +851,7 @@
         },
         "jsdom": {
           "version": "9.8.3",
-          "resolved": "http://registry.npmjs.org/jsdom/-/jsdom-9.8.3.tgz",
+          "resolved": "https://registry.npmjs.org/jsdom/-/jsdom-9.8.3.tgz",
           "integrity": "sha1-/eKcEJwyoRMeC2xlkU5kGY+Xw3A=",
           "requires": {
             "abab": "^1.0.0",
@@ -1090,7 +1090,7 @@
         },
         "strip-ansi": {
           "version": "3.0.1",
-          "resolved": "http://registry.npmjs.org/strip-ansi/-/strip-ansi-3.0.1.tgz",
+          "resolved": "https://registry.npmjs.org/strip-ansi/-/strip-ansi-3.0.1.tgz",
           "integrity": "sha1-ajhfuIU9lS1f8F0Oiq+UJ43GPc8=",
           "requires": {
             "ansi-regex": "^2.0.0"
@@ -2259,7 +2259,7 @@
       "dependencies": {
         "combined-stream": {
           "version": "1.0.6",
-          "resolved": "http://registry.npmjs.org/combined-stream/-/combined-stream-1.0.6.tgz",
+          "resolved": "https://registry.npmjs.org/combined-stream/-/combined-stream-1.0.6.tgz",
           "integrity": "sha1-cj599ugBrFYTETp+RFqbactjKBg=",
           "requires": {
             "delayed-stream": "~1.0.0"
@@ -2325,7 +2325,8 @@
         "ansi-regex": {
           "version": "2.1.1",
           "bundled": true,
-          "dev": true
+          "dev": true,
+          "optional": true
         },
         "aproba": {
           "version": "1.2.0",
@@ -2346,12 +2347,14 @@
         "balanced-match": {
           "version": "1.0.0",
           "bundled": true,
-          "dev": true
+          "dev": true,
+          "optional": true
         },
         "brace-expansion": {
           "version": "1.1.11",
           "bundled": true,
           "dev": true,
+          "optional": true,
           "requires": {
             "balanced-match": "^1.0.0",
             "concat-map": "0.0.1"
@@ -2366,17 +2369,20 @@
         "code-point-at": {
           "version": "1.1.0",
           "bundled": true,
-          "dev": true
+          "dev": true,
+          "optional": true
         },
         "concat-map": {
           "version": "0.0.1",
           "bundled": true,
-          "dev": true
+          "dev": true,
+          "optional": true
         },
         "console-control-strings": {
           "version": "1.1.0",
           "bundled": true,
-          "dev": true
+          "dev": true,
+          "optional": true
         },
         "core-util-is": {
           "version": "1.0.2",
@@ -2493,7 +2499,8 @@
         "inherits": {
           "version": "2.0.3",
           "bundled": true,
-          "dev": true
+          "dev": true,
+          "optional": true
         },
         "ini": {
           "version": "1.3.5",
@@ -2505,6 +2512,7 @@
           "version": "1.0.0",
           "bundled": true,
           "dev": true,
+          "optional": true,
           "requires": {
             "number-is-nan": "^1.0.0"
           }
@@ -2519,6 +2527,7 @@
           "version": "3.0.4",
           "bundled": true,
           "dev": true,
+          "optional": true,
           "requires": {
             "brace-expansion": "^1.1.7"
           }
@@ -2526,12 +2535,14 @@
         "minimist": {
           "version": "0.0.8",
           "bundled": true,
-          "dev": true
+          "dev": true,
+          "optional": true
         },
         "minipass": {
           "version": "2.2.4",
           "bundled": true,
           "dev": true,
+          "optional": true,
           "requires": {
             "safe-buffer": "^5.1.1",
             "yallist": "^3.0.0"
@@ -2550,6 +2561,7 @@
           "version": "0.5.1",
           "bundled": true,
           "dev": true,
+          "optional": true,
           "requires": {
             "minimist": "0.0.8"
           }
@@ -2630,7 +2642,8 @@
         "number-is-nan": {
           "version": "1.0.1",
           "bundled": true,
-          "dev": true
+          "dev": true,
+          "optional": true
         },
         "object-assign": {
           "version": "4.1.1",
@@ -2642,6 +2655,7 @@
           "version": "1.4.0",
           "bundled": true,
           "dev": true,
+          "optional": true,
           "requires": {
             "wrappy": "1"
           }
@@ -2727,7 +2741,8 @@
         "safe-buffer": {
           "version": "5.1.1",
           "bundled": true,
-          "dev": true
+          "dev": true,
+          "optional": true
         },
         "safer-buffer": {
           "version": "2.1.2",
@@ -2763,6 +2778,7 @@
           "version": "1.0.2",
           "bundled": true,
           "dev": true,
+          "optional": true,
           "requires": {
             "code-point-at": "^1.0.0",
             "is-fullwidth-code-point": "^1.0.0",
@@ -2782,6 +2798,7 @@
           "version": "3.0.1",
           "bundled": true,
           "dev": true,
+          "optional": true,
           "requires": {
             "ansi-regex": "^2.0.0"
           }
@@ -2825,12 +2842,14 @@
         "wrappy": {
           "version": "1.0.2",
           "bundled": true,
-          "dev": true
+          "dev": true,
+          "optional": true
         },
         "yallist": {
           "version": "3.0.2",
           "bundled": true,
-          "dev": true
+          "dev": true,
+          "optional": true
         }
       }
     },
@@ -4180,9 +4199,33 @@
       "dev": true
     },
     "node-fetch": {
-      "version": "2.2.0",
-      "resolved": "https://registry.npmjs.org/node-fetch/-/node-fetch-2.2.0.tgz",
-      "integrity": "sha512-OayFWziIxiHY8bCUyLX6sTpDH8Jsbp4FfYd1j1f7vZyfgkcOnAyM4oQR16f8a0s7Gl/viMGRey8eScYk4V4EZA=="
+      "version": "2.6.7",
+      "resolved": "https://registry.npmjs.org/node-fetch/-/node-fetch-2.6.7.tgz",
+      "integrity": "sha512-ZjMPFEfVx5j+y2yF35Kzx5sF7kDzxuDj6ziH4FFbOp87zKDZNx8yExJIb05OGF4Nlt9IHFIMBkRl41VdvcNdbQ==",
+      "requires": {
+        "whatwg-url": "^5.0.0"
+      },
+      "dependencies": {
+        "tr46": {
+          "version": "0.0.3",
+          "resolved": "https://registry.npmjs.org/tr46/-/tr46-0.0.3.tgz",
+          "integrity": "sha512-N3WMsuqV66lT30CrXNbEjx4GEwlow3v6rr4mCcv6prnfwhS01rkgyFdjPNBYd9br7LpXV1+Emh01fHnq2Gdgrw=="
+        },
+        "webidl-conversions": {
+          "version": "3.0.1",
+          "resolved": "https://registry.npmjs.org/webidl-conversions/-/webidl-conversions-3.0.1.tgz",
+          "integrity": "sha512-2JAn3z8AR6rjK8Sm8orRC0h/bcl/DqL7tRPdGZ4I1CjdF+EaMLmYxBHyXuKL849eucPFhvBoxMsflfOb8kxaeQ=="
+        },
+        "whatwg-url": {
+          "version": "5.0.0",
+          "resolved": "https://registry.npmjs.org/whatwg-url/-/whatwg-url-5.0.0.tgz",
+          "integrity": "sha512-saE57nupxk6v3HY35+jzBwYa0rKSy0XR8JSxZPwgLr7ys0IBzhGviA1/TUGJLmSVqs8pb9AnvICXEuOHLprYTw==",
+          "requires": {
+            "tr46": "~0.0.3",
+            "webidl-conversions": "^3.0.0"
+          }
+        }
+      }
     },
     "node-pre-gyp": {
       "version": "0.10.3",
@@ -6275,7 +6318,7 @@
         },
         "strip-ansi": {
           "version": "3.0.1",
-          "resolved": "http://registry.npmjs.org/strip-ansi/-/strip-ansi-3.0.1.tgz",
+          "resolved": "https://registry.npmjs.org/strip-ansi/-/strip-ansi-3.0.1.tgz",
           "integrity": "sha1-ajhfuIU9lS1f8F0Oiq+UJ43GPc8=",
           "requires": {
             "ansi-regex": "^2.0.0"
@@ -6413,7 +6456,7 @@
         },
         "strip-ansi": {
           "version": "3.0.1",
-          "resolved": "http://registry.npmjs.org/strip-ansi/-/strip-ansi-3.0.1.tgz",
+          "resolved": "https://registry.npmjs.org/strip-ansi/-/strip-ansi-3.0.1.tgz",
           "integrity": "sha1-ajhfuIU9lS1f8F0Oiq+UJ43GPc8=",
           "requires": {
             "ansi-regex": "^2.0.0"
diff --git a/package.json b/package.json
index 43e8e8c..ee61e74 100644
--- a/package.json
+++ b/package.json
@@ -41,7 +41,7 @@
     "lodash": "^4.17.10",
     "mathjax-node-svg2png": "^2.0.0",
     "moment": "^2.22.2",
-    "node-fetch": "^2.2.0",
+    "node-fetch": "^2.6.7",
     "node-schedule": "^1.3.1",
     "pluralize": "^7.0.0",
     "prettier": "^1.13.7",