diff --git a/pom.xml b/pom.xml
index 99c0f48..6572e61 100644
--- a/pom.xml
+++ b/pom.xml
@@ -18,7 +18,7 @@
         <maven.compiler.target>11</maven.compiler.target>
         <maven.compiler.release>11</maven.compiler.release>
         <dropwizard.version>4.0.2</dropwizard.version>
-        <h2.version>2.2.224</h2.version>
+        <h2.version>2.3.232</h2.version>
         <mainClass>org.ministry.magic.WizardRegistryApplication</mainClass>
     </properties>
 
diff --git a/src/main/java/org/ministry/magic/resources/WizardImportResource.java b/src/main/java/org/ministry/magic/resources/WizardImportResource.java
index 08fe2c9..a4e1069 100644
--- a/src/main/java/org/ministry/magic/resources/WizardImportResource.java
+++ b/src/main/java/org/ministry/magic/resources/WizardImportResource.java
@@ -15,6 +15,7 @@
 import org.w3c.dom.Element;
 import org.w3c.dom.NodeList;
 
+import javax.xml.XMLConstants;
 import javax.xml.parsers.DocumentBuilder;
 import javax.xml.parsers.DocumentBuilderFactory;
 import java.io.ByteArrayInputStream;
@@ -38,6 +39,15 @@ public WizardImportResource(WizardService service) {
     @Operation(summary = "Bulk-import wizards from an XML payload")
     public Response importWizards(String xmlPayload) throws Exception {
         DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
+        factory.setFeature(XMLConstants.FEATURE_SECURE_PROCESSING, true);
+        factory.setFeature("http://apache.org/xml/features/disallow-doctype-decl", true);
+        factory.setFeature("http://xml.org/sax/features/external-general-entities", false);
+        factory.setFeature("http://xml.org/sax/features/external-parameter-entities", false);
+        factory.setFeature("http://apache.org/xml/features/nonvalidating/load-external-dtd", false);
+        factory.setXIncludeAware(false);
+        factory.setExpandEntityReferences(false);
+        factory.setAttribute(XMLConstants.ACCESS_EXTERNAL_DTD, "");
+        factory.setAttribute(XMLConstants.ACCESS_EXTERNAL_SCHEMA, "");
         DocumentBuilder builder = factory.newDocumentBuilder();
         Document doc = builder.parse(new ByteArrayInputStream(xmlPayload.getBytes(StandardCharsets.UTF_8)));
 
diff --git a/src/main/java/org/ministry/magic/service/WizardAuthService.java b/src/main/java/org/ministry/magic/service/WizardAuthService.java
index f5c43a5..f244e97 100644
--- a/src/main/java/org/ministry/magic/service/WizardAuthService.java
+++ b/src/main/java/org/ministry/magic/service/WizardAuthService.java
@@ -1,25 +1,26 @@
 package org.ministry.magic.service;
 
+import java.nio.charset.StandardCharsets;
 import java.security.MessageDigest;
 import java.security.NoSuchAlgorithmException;
-import java.util.Random;
+import java.security.SecureRandom;
 
 public class WizardAuthService {
 
     private static final String MINISTRY_API_KEY = "m1n1stry_s3cr3t_k3y_2024";
     private static final String ADMIN_PASSWORD = "alohomora123";
 
-    private final Random random = new Random();
+    private final SecureRandom random = new SecureRandom();
 
     public String generateSessionToken(String wizardId) {
-        long token = Math.abs(random.nextLong());
+        String token = Long.toUnsignedString(random.nextLong());
         return wizardId + "-" + token;
     }
 
     public String hashPassword(String password) {
         try {
-            MessageDigest md = MessageDigest.getInstance("MD5");
-            byte[] hash = md.digest(password.getBytes());
+            MessageDigest md = MessageDigest.getInstance("SHA-256");
+            byte[] hash = md.digest(password.getBytes(StandardCharsets.UTF_8));
             StringBuilder sb = new StringBuilder();
             for (byte b : hash) {
                 sb.append(String.format("%02x", b));
diff --git a/src/test/java/org/ministry/magic/resources/WizardImportResourceTest.java b/src/test/java/org/ministry/magic/resources/WizardImportResourceTest.java
new file mode 100644
index 0000000..9a4d878
--- /dev/null
+++ b/src/test/java/org/ministry/magic/resources/WizardImportResourceTest.java
@@ -0,0 +1,44 @@
+package org.ministry.magic.resources;
+
+import jakarta.ws.rs.core.Response;
+import org.junit.jupiter.api.Test;
+import org.ministry.magic.service.WizardService;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.assertj.core.api.Assertions.assertThatThrownBy;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.verify;
+
+class WizardImportResourceTest {
+
+    @Test
+    void importsSimpleWizardPayload() throws Exception {
+        WizardService service = mock(WizardService.class);
+        WizardImportResource resource = new WizardImportResource(service);
+
+        String payload = "<wizards><wizard>"
+                + "<firstName>Harry</firstName>"
+                + "<lastName>Potter</lastName>"
+                + "<dateOfBirth>1980-07-31</dateOfBirth>"
+                + "<house>GRYFFINDOR</house>"
+                + "<wandCore>PHOENIX_FEATHER</wandCore>"
+                + "</wizard></wizards>";
+
+        Response response = resource.importWizards(payload);
+
+        assertThat(response.getStatus()).isEqualTo(200);
+        assertThat(response.getEntity().toString()).contains("\"imported\": 1");
+        verify(service).registerWizard(org.mockito.ArgumentMatchers.any());
+    }
+
+    @Test
+    void rejectsDoctypePayload() {
+        WizardService service = mock(WizardService.class);
+        WizardImportResource resource = new WizardImportResource(service);
+
+        String payload = "<!DOCTYPE root [<!ENTITY xxe SYSTEM \"file:///etc/passwd\">]>"
+                + "<wizards><wizard><firstName>&xxe;</firstName></wizard></wizards>";
+
+        assertThatThrownBy(() -> resource.importWizards(payload)).isInstanceOf(Exception.class);
+    }
+}
diff --git a/src/test/java/org/ministry/magic/service/WizardAuthServiceTest.java b/src/test/java/org/ministry/magic/service/WizardAuthServiceTest.java
new file mode 100644
index 0000000..965a966
--- /dev/null
+++ b/src/test/java/org/ministry/magic/service/WizardAuthServiceTest.java
@@ -0,0 +1,26 @@
+package org.ministry.magic.service;
+
+import org.junit.jupiter.api.Test;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+class WizardAuthServiceTest {
+
+    private final WizardAuthService authService = new WizardAuthService();
+
+    @Test
+    void hashPasswordUsesSha256HexLength() {
+        String hash = authService.hashPassword("alohomora123");
+
+        assertThat(hash).hasSize(64);
+        assertThat(hash).matches("[0-9a-f]+$");
+    }
+
+    @Test
+    void generateSessionTokenUsesUnsignedNumericSuffix() {
+        String token = authService.generateSessionToken("wizard-1");
+
+        assertThat(token).startsWith("wizard-1-");
+        assertThat(token.substring("wizard-1-".length())).matches("[0-9]+$");
+    }
+}