diff --git a/src/Umbraco.Core/Configuration/Models/SecuritySettings.cs b/src/Umbraco.Core/Configuration/Models/SecuritySettings.cs
index 9570676ebaa2..ac0727889dc4 100644
--- a/src/Umbraco.Core/Configuration/Models/SecuritySettings.cs
+++ b/src/Umbraco.Core/Configuration/Models/SecuritySettings.cs
@@ -139,6 +139,7 @@ public class SecuritySettings
     /// The user login endpoint ensures that failed login attempts take at least as long as the average successful login.
     /// However, if no successful logins have occurred, this value is used as the default duration.
     /// </remarks>
+    [Range(0, int.MaxValue)] // TODO (V17): Change property type to short and update maximum range to short.MaxValue
     [DefaultValue(StaticUserDefaultFailedLoginDurationInMilliseconds)]
     public long UserDefaultFailedLoginDurationInMilliseconds { get; set; } = StaticUserDefaultFailedLoginDurationInMilliseconds;
 
@@ -148,6 +149,7 @@ public class SecuritySettings
     /// <value>
     /// The minimum duration (in milliseconds) of failed login attempts.
     /// </value>
+    [Range(0, int.MaxValue)] // TODO (V17): Change property type to short and update maximum range to short.MaxValue
     [DefaultValue(StaticUserMinimumFailedLoginDurationInMilliseconds)]
     public long UserMinimumFailedLoginDurationInMilliseconds { get; set; } = StaticUserMinimumFailedLoginDurationInMilliseconds;
 }
diff --git a/src/Umbraco.Core/TimedScope.cs b/src/Umbraco.Core/TimedScope.cs
index f12f0e90eda8..6cd009f3035c 100644
--- a/src/Umbraco.Core/TimedScope.cs
+++ b/src/Umbraco.Core/TimedScope.cs
@@ -133,6 +133,8 @@ public void Dispose()
         {
             Thread.Sleep(remaining);
         }
+
+        _cancellationTokenSource.Dispose();
     }
 
     /// <summary>
@@ -151,6 +153,8 @@ public async ValueTask DisposeAsync()
         {
             await Task.Delay(remaining, _timeProvider, _cancellationTokenSource.Token).ConfigureAwait(false);
         }
+
+        _cancellationTokenSource.Dispose();
     }
 
     private bool TryGetRemaining(out TimeSpan remaining)
diff --git a/src/Umbraco.Web.BackOffice/Controllers/AuthenticationController.cs b/src/Umbraco.Web.BackOffice/Controllers/AuthenticationController.cs
index 484a80ac7ef0..ca9cfedf3615 100644
--- a/src/Umbraco.Web.BackOffice/Controllers/AuthenticationController.cs
+++ b/src/Umbraco.Web.BackOffice/Controllers/AuthenticationController.cs
@@ -74,7 +74,6 @@ public class AuthenticationController : UmbracoApiControllerBase
     private readonly IUserService _userService;
     private readonly WebRoutingSettings _webRoutingSettings;
 
-    private const int FailedLoginDurationRandomOffsetInMilliseconds = 100;
     private static long? _loginDurationAverage;
 
     // TODO: We need to review all _userManager.Raise calls since many/most should be on the usermanager or signinmanager, very few should be here
@@ -419,13 +418,12 @@ public async Task<bool> IsAuthenticated()
     public async Task<ActionResult<UserDetail?>> PostLogin(LoginModel loginModel)
     {
         // Start a timed scope to ensure failed responses return is a consistent time
-        await using var timedScope = new TimedScope(GetLoginDuration(), CancellationToken.None);
+        var loginDuration = Math.Max(_loginDurationAverage ?? _securitySettings.UserDefaultFailedLoginDurationInMilliseconds, _securitySettings.UserMinimumFailedLoginDurationInMilliseconds);
+        await using var timedScope = new TimedScope(loginDuration, HttpContext.RequestAborted);
 
         // Sign the user in with username/password, this also gives a chance for developers to
         // custom verify the credentials and auto-link user accounts with a custom IBackOfficePasswordChecker
-        SignInResult result = await _signInManager.PasswordSignInAsync(
-            loginModel.Username, loginModel.Password, true, true);
-
+        SignInResult result = await _signInManager.PasswordSignInAsync(loginModel.Username, loginModel.Password, true, true);
         if (result.Succeeded is false)
         {
             BackOfficeIdentityUser? user = await _userManager.FindByNameAsync(loginModel.Username.Trim());
@@ -476,22 +474,6 @@ await _userManager.CheckPasswordAsync(user, loginModel.Password))
         return GetUserDetail(_userService.GetByUsername(loginModel.Username));
     }
 
-    private long GetLoginDuration()
-    {
-        var loginDuration = Math.Max(_loginDurationAverage ?? _securitySettings.UserDefaultFailedLoginDurationInMilliseconds, _securitySettings.UserMinimumFailedLoginDurationInMilliseconds);
-        var random = new Random();
-        var randomDelay = random.Next(-FailedLoginDurationRandomOffsetInMilliseconds, FailedLoginDurationRandomOffsetInMilliseconds);
-        loginDuration += randomDelay;
-
-        // Just be sure we don't get a negative number - possible if someone has configured a very low UserMinimumFailedLoginDurationInMilliseconds value.
-        if (loginDuration < 0)
-        {
-            loginDuration = 0;
-        }
-
-        return loginDuration;
-    }
-
     /// <summary>
     ///     Processes a password reset request.  Looks for a match on the provided email address
     ///     and if found sends an email with a link to reset it