diff --git a/elixir/apps/domain/lib/domain/auth/adapters/email.ex b/elixir/apps/domain/lib/domain/auth/adapters/email.ex
index 4532229e9..be31f3eda 100644
--- a/elixir/apps/domain/lib/domain/auth/adapters/email.ex
+++ b/elixir/apps/domain/lib/domain/auth/adapters/email.ex
@@ -100,18 +100,25 @@ defmodule Domain.Auth.Adapters.Email do
 
   @impl true
   def verify_secret(%Identity{} = identity, %Context{} = context, encoded_token) do
-    with {:ok, token} <- Tokens.use_token(encoded_token, %{context | type: :email}) do
+    with {:ok, token} <- Tokens.use_token(encoded_token, %{context | type: :email}),
+         true <- token.identity_id == identity.id do
       {:ok, identity} =
-        Identity.Changeset.update_identity_provider_state(identity, %{
-          last_used_token_id: token.id
-        })
-        |> Repo.update()
+        Identity.Query.not_disabled()
+        |> Identity.Query.by_id(identity.id)
+        |> Repo.fetch_and_update(Identity.Query,
+          with: fn identity ->
+            Identity.Changeset.update_identity_provider_state(identity, %{
+              last_used_token_id: token.id
+            })
+          end
+        )
 
       {:ok, _count} = Tokens.delete_all_tokens_by_type_and_assoc(:email, identity)
 
       {:ok, identity, nil}
     else
       {:error, :invalid_or_expired_token} -> {:error, :invalid_secret}
+      false -> {:error, :invalid_secret}
     end
   end
 end
diff --git a/elixir/apps/domain/test/domain/auth/adapters/email_test.exs b/elixir/apps/domain/test/domain/auth/adapters/email_test.exs
index 032a3468c..45b1cecb5 100644
--- a/elixir/apps/domain/test/domain/auth/adapters/email_test.exs
+++ b/elixir/apps/domain/test/domain/auth/adapters/email_test.exs
@@ -176,6 +176,22 @@ defmodule Domain.Auth.Adapters.EmailTest do
       assert token.deleted_at
     end
 
+    test "returns error when token belongs to a different identity", %{
+      account: account,
+      provider: provider,
+      identity: identity,
+      context: context
+    } do
+      other_identity = Fixtures.Auth.create_identity(account: account, provider: provider)
+      {:ok, other_identity} = request_sign_in_token(other_identity, context)
+
+      nonce = other_identity.provider_virtual_state.nonce
+      fragment = other_identity.provider_virtual_state.fragment
+      token = nonce <> fragment
+
+      assert verify_secret(identity, context, token) == {:error, :invalid_secret}
+    end
+
     test "returns error when token is expired", %{
       context: context,
       identity: identity,
diff --git a/elixir/apps/domain/test/domain/auth_test.exs b/elixir/apps/domain/test/domain/auth_test.exs
index 40a441e0b..407259f2f 100644
--- a/elixir/apps/domain/test/domain/auth_test.exs
+++ b/elixir/apps/domain/test/domain/auth_test.exs
@@ -2989,6 +2989,26 @@ defmodule Domain.AuthTest do
                {:error, :unauthorized}
     end
 
+    test "returns error when secret belongs to a different identity invalid", %{
+      account: account,
+      provider: provider,
+      user_agent: user_agent,
+      remote_ip: remote_ip
+    } do
+      nonce = "test_nonce_for_firezone"
+      context = %Auth.Context{type: :browser, user_agent: user_agent, remote_ip: remote_ip}
+
+      identity = Fixtures.Auth.create_identity(account: account, provider: provider)
+      {:ok, identity} = Domain.Auth.Adapters.Email.request_sign_in_token(identity, context)
+
+      identity2 = Fixtures.Auth.create_identity(account: account, provider: provider)
+      {:ok, identity2} = Domain.Auth.Adapters.Email.request_sign_in_token(identity2, context)
+      secret = identity2.provider_virtual_state.nonce <> identity2.provider_virtual_state.fragment
+
+      assert sign_in(provider, identity.provider_identifier, nonce, secret, context) ==
+               {:error, :unauthorized}
+    end
+
     test "returns error when nonce is invalid", %{
       account: account,
       provider: provider,
diff --git a/elixir/mix.exs b/elixir/mix.exs
index 3e19c093e..a1dfa7c18 100644
--- a/elixir/mix.exs
+++ b/elixir/mix.exs
@@ -1,11 +1,13 @@
 defmodule Firezone.MixProject do
   use Mix.Project
 
+  @version "VERSION" |> File.read!() |> String.trim()
+
   def project do
     [
       name: :firezone,
       apps_path: "apps",
-      version: String.trim(File.read!("VERSION")),
+      version: @version,
       start_permanent: Mix.env() == :prod,
       test_coverage: [tool: ExCoveralls],
       preferred_cli_env: [