diff --git a/composer.json b/composer.json
index b7a96f0f..9ecf4c38 100644
--- a/composer.json
+++ b/composer.json
@@ -8,7 +8,7 @@
         "robmorgan/phinx": "^0.14",
         "google/cloud-storage": "^1.48",
         "opencensus/opencensus-exporter-stackdriver": "^0.1.0",
-        "smarty/smarty": "^4.5.3",
+        "smarty/smarty": "^5.5.2",
         "sendgrid/sendgrid": "^8.1",
         "google/cloud-logging": "1.28.*",
         "auth0/auth0-php": "^8.0.5",
diff --git a/composer.lock b/composer.lock
index b27aeec3..19b3dbb2 100644
--- a/composer.lock
+++ b/composer.lock
@@ -4,7 +4,7 @@
         "Read more about it at https://getcomposer.org/doc/01-basic-usage.md#installing-dependencies",
         "This file is @generated automatically"
     ],
-    "content-hash": "f91fea22b3c74dfb0d239a77c354058d",
+    "content-hash": "473d00248e49aefda6fed3a06f078132",
     "packages": [
         {
             "name": "auth0/auth0-php",
@@ -4587,35 +4587,39 @@
         },
         {
             "name": "smarty/smarty",
-            "version": "v4.5.6",
+            "version": "v5.5.2",
             "source": {
                 "type": "git",
                 "url": "https://github.com/smarty-php/smarty.git",
-                "reference": "a8d77c86660ca0562ec2fb781fbbda737fb7a62b"
+                "reference": "0e46ae3add2c6213612951464b4edc44828fbc01"
             },
             "dist": {
                 "type": "zip",
-                "url": "https://api.github.com/repos/smarty-php/smarty/zipball/a8d77c86660ca0562ec2fb781fbbda737fb7a62b",
-                "reference": "a8d77c86660ca0562ec2fb781fbbda737fb7a62b",
+                "url": "https://api.github.com/repos/smarty-php/smarty/zipball/0e46ae3add2c6213612951464b4edc44828fbc01",
+                "reference": "0e46ae3add2c6213612951464b4edc44828fbc01",
                 "shasum": ""
             },
             "require": {
-                "php": "^7.1 || ^8.0"
+                "php": "^7.2 || ^8.0",
+                "symfony/polyfill-mbstring": "^1.27"
             },
             "require-dev": {
                 "phpunit/phpunit": "^8.5 || ^7.5",
-                "smarty/smarty-lexer": "^3.1"
+                "smarty/smarty-lexer": "^4.0.2"
             },
             "type": "library",
             "extra": {
                 "branch-alias": {
-                    "dev-master": "4.0.x-dev"
+                    "dev-master": "5.0.x-dev"
                 }
             },
             "autoload": {
-                "classmap": [
-                    "libs/"
-                ]
+                "files": [
+                    "src/functions.php"
+                ],
+                "psr-4": {
+                    "Smarty\\": "src/"
+                }
             },
             "notification-url": "https://packagist.org/downloads/",
             "license": [
@@ -4647,7 +4651,7 @@
             "support": {
                 "forum": "https://github.com/smarty-php/smarty/discussions",
                 "issues": "https://github.com/smarty-php/smarty/issues",
-                "source": "https://github.com/smarty-php/smarty/tree/v4.5.6"
+                "source": "https://github.com/smarty-php/smarty/tree/v5.5.2"
             },
             "funding": [
                 {
@@ -4655,7 +4659,7 @@
                     "type": "github"
                 }
             ],
-            "time": "2025-08-26T08:37:46+00:00"
+            "time": "2025-08-26T08:38:06+00:00"
         },
         {
             "name": "starkbank/ecdsa",