diff --git a/server/config/passport.js b/server/config/passport.js
index ea8163e975..87dd8e49a1 100644
--- a/server/config/passport.js
+++ b/server/config/passport.js
@@ -124,6 +124,18 @@ const getVerifiedEmails = (githubEmails) =>
 const getPrimaryEmail = (githubEmails) =>
   (lodash.find(githubEmails, { primary: true }) || {}).value;
 
+/**
+ * Get primary email from Google OAuth profile.
+ * Returns the first email if available, or null if emails array is missing/empty.
+ */
+const getGooglePrimaryEmail = (googleEmails) => {
+  if (!Array.isArray(googleEmails) || googleEmails.length === 0) {
+    return null;
+  }
+  const primaryEmail = googleEmails[0]?.value?.trim();
+  return primaryEmail || null;
+};
+
 /**
  * Sign in with GitHub.
  */
@@ -240,8 +252,18 @@ passport.use(
     },
     async (req, accessToken, refreshToken, profile, done) => {
       try {
+        // Validate that emails array exists and has at least one element
+        const primaryEmail = getGooglePrimaryEmail(profile._json?.emails);
+        if (!primaryEmail) {
+          return done(null, false, {
+            msg:
+              'Unable to retrieve email from Google account. ' +
+              'Please ensure your Google account has an email address and try again.'
+          });
+        }
+
         const existingUser = await User.findOne({
-          google: profile._json.emails[0].value
+          google: primaryEmail
         }).exec();
 
         if (existingUser) {
@@ -258,18 +280,16 @@ passport.use(
           return done(null, existingUser);
         }
 
-        const primaryEmail = profile._json.emails[0].value;
-
         if (req.user) {
           if (!req.user.google) {
-            req.user.google = profile._json.emails[0].value;
+            req.user.google = primaryEmail;
             req.user.tokens.push({ kind: 'google', accessToken });
             req.user.verified = User.EmailConfirmation().Verified;
           }
           await req.user.save();
           return done(null, req.user);
         }
-        let username = profile._json.emails[0].value.split('@')[0];
+        let username = primaryEmail.split('@')[0];
         const existingEmailUser = await User.findByEmail(primaryEmail);
         const existingUsernameUser = await User.findByUsername(username, {
           caseInsensitive: true
@@ -285,7 +305,7 @@ passport.use(
             return done(null, false, { msg: accountSuspensionMessage });
           }
           existingEmailUser.email = existingEmailUser.email || primaryEmail;
-          existingEmailUser.google = profile._json.emails[0].value;
+          existingEmailUser.google = primaryEmail;
           existingEmailUser.username = existingEmailUser.username || username;
           existingEmailUser.tokens.push({
             kind: 'google',
@@ -301,7 +321,7 @@ passport.use(
 
         const user = new User();
         user.email = primaryEmail;
-        user.google = profile._json.emails[0].value;
+        user.google = primaryEmail;
         user.username = username;
         user.tokens.push({ kind: 'google', accessToken });
         user.name = profile._json.displayName;