# UNDF: UNDF-2026-000001000
--- a/src/tech.c
+++ b/src/tech.c
@@ -656,6 +656,12 @@
  * @brief Recursive function for creating an array of commodities from a tech
  * group.
+ *
+ * CWE-407: The inner dedup loop at "Skip if already in list" scans the
+ * entire output array for every item, making this O(I * N) where I is the
+ * number of items across all tech groups and N is the growing output size.
+ * Fix: track seen pointers in a sorted array and use bsearch for O(log N)
+ * dedup instead of O(N) linear scan.
  */
 static void **tech_addGroupItemPrice( void **items, double **price,
                                       tech_item_type_t    type,
@@ -678,8 +684,9 @@
       if ( tech_testCond( item, search ) )
          continue;

-      /* Skip if already in list. */
+      /* Skip if already in list.
+       * DEFECTIVE: linear scan of output array per item = O(I * N). */
       f = 0;
-      /* Count backwards so the price of newly added stuff is more important. */
+      /* Count backwards so the price of newly added stuff takes precedence. */
       for ( int j = array_size( items ) - 1; j >= 0; j-- ) {
          if ( items[j] == item->u.ptr ) {
             f = 1;