diff --git a/CHANGELOG.md b/CHANGELOG.md
index bd46315b9e..b1b64f5f0a 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -5,6 +5,12 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](http://keepachangelog.com/)
 and this project adheres to [Semantic Versioning](http://semver.org/).
 
+## [Unreleased]
+
+### Fixed
+
+- Order detail price and discount updates are now restricted to items of the current order
+
 ## [2.12.10] - 2026-09-11
 
 ### Fixed
diff --git a/front/order.form.php b/front/order.form.php
index 9da80460ad..445c137e52 100644
--- a/front/order.form.php
+++ b/front/order.form.php
@@ -456,8 +456,17 @@
     Html::back();
 } elseif (isset($_POST["update_detail_item"])) {
     $pluginOrderOrder->check($_POST["plugin_order_orders_id"], UPDATE);
+    $orders_id = (int) $_POST["plugin_order_orders_id"];
+
     if (isset($_POST['detail_price_taxfree'])) {
         foreach ($_POST['detail_price_taxfree'] as $item_id => $price) {
+            if (
+                !$pluginOrderOrder_Item->getFromDB($item_id)
+                || !$pluginOrderOrder_Item->belongsToOrder($orders_id)
+            ) {
+                continue;
+            }
+
             $pluginOrderOrder_Item->updatePrice_taxfree([
                 'item_id'       => $item_id,
                 'price_taxfree' => $price,
@@ -467,6 +476,13 @@
 
     if (isset($_POST['detail_discount'])) {
         foreach ($_POST['detail_discount'] as $item_id => $discount) {
+            if (
+                !$pluginOrderOrder_Item->getFromDB($item_id)
+                || !$pluginOrderOrder_Item->belongsToOrder($orders_id)
+            ) {
+                continue;
+            }
+
             $pluginOrderOrder_Item->updateDiscount([
                 'item_id'  => $item_id,
                 'discount' => $discount,