diff --git a/README.md b/README.md
index b1cce59f0..8eb6379f9 100644
--- a/README.md
+++ b/README.md
@@ -73,6 +73,7 @@ cd gnuboard5
 
 ## 문서 및 지원
 
+- [5.6.391 쇼핑몰 분류 표시 수정 안내](docs/release-5.6.391.md)
 - [5.6.39 보안 업데이트 및 필수 DB업그레이드 안내](docs/release-5.6.39.md)
 
 - [5.6.37 SIRK 전용 카카오페이 연동 종료 및 기존 거래 지원](docs/sirk-kakaopay-retirement.md)
diff --git a/docs/release-5.6.391.md b/docs/release-5.6.391.md
new file mode 100644
index 000000000..d9f4dee6c
--- /dev/null
+++ b/docs/release-5.6.391.md
@@ -0,0 +1,26 @@
+# 그누보드(영카트) 5.6.391 배포 안내
+
+배포일: 2026-09-15. 변경 기준은 5.6.39입니다.
+
+쇼핑몰 4·5단계 분류의 현재 경로와 서브메뉴 표시를 보완하는 버그 수정 버전입니다.
+
+## 변경 사항
+
+- PC 기본 스킨과 basic 테마의 breadcrumb에 4·5단계 분류 경로를 표시합니다. 모든 단계에서 기존 위치와 스타일을 유지합니다.
+- PC·모바일 기본 스킨과 basic 테마의 서브메뉴는 선택한 4단계에 사용 중인 5단계가 있으면 5단계 목록만 표시하고, 없으면 4단계 형제 목록만 표시합니다.
+- 5단계에서는 같은 부모 아래의 5단계 형제 목록과 현재 선택을 표시합니다.
+- 공통 전체 분류 트리의 기존 3단계 구조는 유지하고 현재 경로에 필요한 깊은 단계만 추가 조회합니다.
+
+## 업데이트 방법
+
+1. 기존 소스와 사용자 수정 파일을 백업합니다.
+2. 5.6.39 설치본에 전체 소스 또는 `gnuboard5.6.391.patch.zip`을 반영합니다. 공통 라이브러리와 스킨 파일을 함께 업데이트합니다. 사용자 수정 스킨은 변경 내용을 비교하여 병합합니다.
+3. 4·5단계 분류의 breadcrumb, 하위 분류 유무에 따른 메뉴, 현재 선택 표시를 확인합니다.
+
+이번 버전의 추가 DB 마이그레이션과 삭제 대상 파일은 없습니다. 5.6.39보다 오래된 설치본은 [5.6.39 보안 업데이트 및 DB업그레이드 안내](release-5.6.39.md)를 포함한 선행 업데이트를 적용해야 합니다.
+
+## 검증
+
+8개 분류 경로에서 PC·basic 테마의 목록/상세 breadcrumb와 네 스킨의 메뉴·선택 상태를 확인했습니다. Chromium에서 1·3·4·5단계 전환 시 breadcrumb 위치·높이와 메뉴·상품 정렬 영역 위치가 동일함을 확인했습니다. 변경된 운영 PHP 7개 파일은 현재 PHP와 PHP 5.2 구문 검사를 통과했습니다.
+
+분류 데이터 대역을 사용한 회귀 검사이며 실제 운영 DB와 모든 사용자 스킨을 검증한 결과는 아닙니다.
diff --git a/lib/shop.data.lib.php b/lib/shop.data.lib.php
index 4eef513b1..1cc638768 100644
--- a/lib/shop.data.lib.php
+++ b/lib/shop.data.lib.php
@@ -82,9 +82,49 @@ function get_shop_navigation_data($is_cache, $ca_id, $ca_id2='', $ca_id3=''){
         }
     }
 
+    // 공통 전체 분류 트리는 기존 3단계 구조를 유지하고 현재 경로의 깊은 단계만 조회한다.
+    for ($depth = 4; $depth <= 5 && strlen($ca_id) >= $depth * 2; $depth++) {
+        $parent = substr($ca_id, 0, ($depth - 1) * 2);
+        $result = sql_query(get_shop_category_sql($parent, $depth * 2));
+        while ($row = sql_fetch_array($result)) {
+            $row['url'] = shop_category_url($row['ca_id']);
+            $datas[$depth - 1][] = $row;
+        }
+    }
+
     return $datas;
 }
 
+// 4·5단계에서는 선택 경로의 5단계를 우선 표시하고, 없으면 4단계 형제를 표시한다.
+function get_shop_category_menu_groups($ca_id)
+{
+    $length = strlen($ca_id);
+    $groups = array();
+    if ($length >= 8) {
+        $queries = array(
+            array('5단계 분류', substr($ca_id, 0, 8), 10),
+            array('4단계 분류', substr($ca_id, 0, 6), 8),
+        );
+    } else {
+        $queries = array(array('하위 분류', $ca_id, $length + 2));
+    }
+    foreach ($queries as $query) {
+        $rows = array();
+        $result = sql_query(get_shop_category_sql($query[1], $query[2]));
+        while ($row = sql_fetch_array($result)) $rows[] = $row;
+        if (!$rows && $length < 8) {
+            $query[0] = '현재 단계 분류';
+            $result = sql_query(get_shop_category_sql(substr($ca_id, 0, -2), $length));
+            while ($row = sql_fetch_array($result)) $rows[] = $row;
+        }
+        if ($rows) {
+            $groups[] = array('label' => $query[0], 'categories' => $rows);
+            break;
+        }
+    }
+    return $groups;
+}
+
 function get_shop_category_by($is_cache, $case, $value){
     
     if( $case === 'ca_id' ){
@@ -268,4 +308,4 @@ function get_shop_item_options($it_id, $subject, $no)
     }
 
     return $str;
-}
\ No newline at end of file
+}
diff --git a/mobile/skin/shop/basic/listcategory.skin.php b/mobile/skin/shop/basic/listcategory.skin.php
index ddd995594..f966ab733 100644
--- a/mobile/skin/shop/basic/listcategory.skin.php
+++ b/mobile/skin/shop/basic/listcategory.skin.php
@@ -1,44 +1,25 @@
 <?php
-if (!defined("_GNUBOARD_")) exit; // 개별 페이지 접근 불가
+if (!defined('_GNUBOARD_')) exit;
 
-$str = '';
-$exists = false;
-
-$ca_id_len = strlen($ca_id);
-$len2 = $ca_id_len + 2;
-
-$sql = " select ca_id, ca_name from {$g5['g5_shop_category_table']} where ca_id like '$ca_id%' and length(ca_id) = $len2 and ca_use = '1' order by ca_order, ca_id ";
-$result = sql_query($sql);
-
-// 하위 분류가 없으면 현재 분류를 포함한 같은 단계의 사용 중인 분류를 표시한다.
-if (!sql_num_rows($result)) {
-    $parent_ca_id = substr($ca_id, 0, -2);
-    $sql = " select ca_id, ca_name from {$g5['g5_shop_category_table']} where ca_id like '$parent_ca_id%' and length(ca_id) = $ca_id_len and ca_use = '1' order by ca_order, ca_id ";
-    $result = sql_query($sql);
-}
-
-while ($row=sql_fetch_array($result)) {
-
-    $row2 = sql_fetch(" select count(*) as cnt from {$g5['g5_shop_item_table']} where (ca_id like '{$row['ca_id']}%' or ca_id2 like '{$row['ca_id']}%' or ca_id3 like '{$row['ca_id']}%') and it_use = '1'  ");
-
-    $current_attr = ($row['ca_id'] === $ca_id) ? ' class="sct_ct_here" aria-current="page"' : '';
-    $str .= '<li><a'.$current_attr.' href="'.shop_category_url($row['ca_id']).'">'.$row['ca_name'].' <span class="prd_cnt">'.$row2['cnt'].'</span></a></li>';
-    $exists = true;
-}
-
-if ($exists) {
-
-    // add_stylesheet('css 구문', 출력순서); 숫자가 작을 수록 먼저 출력됨
+$category_groups = get_shop_category_menu_groups($ca_id);
+if ($category_groups) {
     add_stylesheet('<link rel="stylesheet" href="'.G5_SHOP_CSS_URL.'/style.css">', 0);
 ?>
-
-<!-- 상품분류 1 시작 { -->
 <aside id="sct_ct_1" class="sct_ct">
     <h2>현재 상품 분류와 관련된 분류</h2>
-    <ul>
-        <?php echo $str; ?>
+    <?php foreach ($category_groups as $category_group) { ?>
+    <ul aria-label="<?php echo $category_group['label']; ?>">
+        <?php foreach ($category_group['categories'] as $row) {
+            $row2 = sql_fetch(" select count(*) as cnt from {$g5['g5_shop_item_table']} where (ca_id like '{$row['ca_id']}%' or ca_id2 like '{$row['ca_id']}%' or ca_id3 like '{$row['ca_id']}%') and it_use = '1' ");
+            $current_attr = '';
+            if ($row['ca_id'] === $ca_id) {
+                $current_attr = ' class="sct_ct_here" aria-current="page"';
+            } elseif (strpos($ca_id, $row['ca_id']) === 0) {
+                $current_attr = ' class="sct_ct_here sct_ct_parent"';
+            }
+            echo '<li><a'.$current_attr.' href="'.shop_category_url($row['ca_id']).'">'.get_text($row['ca_name']).' <span class="prd_cnt">'.$row2['cnt'].'</span></a></li>';
+        } ?>
     </ul>
+    <?php } ?>
 </aside>
-<!-- } 상품분류 1 끝 -->
-
-<?php }
\ No newline at end of file
+<?php }
diff --git a/skin/shop/basic/listcategory.skin.php b/skin/shop/basic/listcategory.skin.php
index 6f1ad0d40..91f7393ec 100644
--- a/skin/shop/basic/listcategory.skin.php
+++ b/skin/shop/basic/listcategory.skin.php
@@ -1,44 +1,25 @@
 <?php
-if (!defined("_GNUBOARD_")) exit; // 개별 페이지 접근 불가
+if (!defined('_GNUBOARD_')) exit;
 
-$str = '';
-$exists = false;
-
-$ca_id_len = strlen($ca_id);
-$len2 = $ca_id_len + 2;
-
-$sql = " select ca_id, ca_name from {$g5['g5_shop_category_table']} where ca_id like '$ca_id%' and length(ca_id) = $len2 and ca_use = '1' order by ca_order, ca_id ";
-$result = sql_query($sql);
-
-// 하위 분류가 없으면 현재 분류를 포함한 같은 단계의 사용 중인 분류를 표시한다.
-if (!sql_num_rows($result)) {
-    $parent_ca_id = substr($ca_id, 0, -2);
-    $sql = " select ca_id, ca_name from {$g5['g5_shop_category_table']} where ca_id like '$parent_ca_id%' and length(ca_id) = $ca_id_len and ca_use = '1' order by ca_order, ca_id ";
-    $result = sql_query($sql);
-}
-
-while ($row=sql_fetch_array($result)) {
-
-    $row2 = sql_fetch(" select count(*) as cnt from {$g5['g5_shop_item_table']} where (ca_id like '{$row['ca_id']}%' or ca_id2 like '{$row['ca_id']}%' or ca_id3 like '{$row['ca_id']}%') and it_use = '1'  ");
-
-    $current_attr = ($row['ca_id'] === $ca_id) ? ' class="sct_ct_here" aria-current="page"' : '';
-    $str .= '<li><a'.$current_attr.' href="'.shop_category_url($row['ca_id']).'">'.$row['ca_name'].' ('.$row2['cnt'].')</a></li>';
-    $exists = true;
-}
-
-if ($exists) {
-
-    // add_stylesheet('css 구문', 출력순서); 숫자가 작을 수록 먼저 출력됨
+$category_groups = get_shop_category_menu_groups($ca_id);
+if ($category_groups) {
     add_stylesheet('<link rel="stylesheet" href="'.G5_SHOP_SKIN_URL.'/style.css">', 0);
 ?>
-
-<!-- 상품분류 1 시작 { -->
 <aside id="sct_ct_1" class="sct_ct">
     <h2>현재 상품 분류와 관련된 분류</h2>
-    <ul>
-        <?php echo $str; ?>
+    <?php foreach ($category_groups as $category_group) { ?>
+    <ul aria-label="<?php echo $category_group['label']; ?>">
+        <?php foreach ($category_group['categories'] as $row) {
+            $row2 = sql_fetch(" select count(*) as cnt from {$g5['g5_shop_item_table']} where (ca_id like '{$row['ca_id']}%' or ca_id2 like '{$row['ca_id']}%' or ca_id3 like '{$row['ca_id']}%') and it_use = '1' ");
+            $current_attr = '';
+            if ($row['ca_id'] === $ca_id) {
+                $current_attr = ' class="sct_ct_here" aria-current="page"';
+            } elseif (strpos($ca_id, $row['ca_id']) === 0) {
+                $current_attr = ' class="sct_ct_here sct_ct_parent"';
+            }
+            echo '<li><a'.$current_attr.' href="'.shop_category_url($row['ca_id']).'">'.get_text($row['ca_name']).' ('.$row2['cnt'].')</a></li>';
+        } ?>
     </ul>
+    <?php } ?>
 </aside>
-<!-- } 상품분류 1 끝 -->
-
-<?php }
\ No newline at end of file
+<?php }
diff --git a/skin/shop/basic/navigation.skin.php b/skin/shop/basic/navigation.skin.php
index 0d830144d..fa99d54ad 100644
--- a/skin/shop/basic/navigation.skin.php
+++ b/skin/shop/basic/navigation.skin.php
@@ -1,24 +1,9 @@
 <?php
 if (!defined("_GNUBOARD_")) exit; // 개별 페이지 접근 불가
 
-$navi_datas = $ca_ids = array();
-$is_item_view = (isset($it_id) && isset($it) && isset($it['it_id']) && $it_id === $it['it_id']) ? true : false;
-
-if( !$is_item_view && $ca_id ){
-    $navi_datas = get_shop_navigation_data(true, $ca_id);
-    $ca_ids = array(
-        'ca_id' => substr($ca_id,0,2),
-        'ca_id2' => substr($ca_id,0,4),
-        'ca_id3' => substr($ca_id,0,6),
-        );
-} else if( $is_item_view && isset($it) && is_array($it) ) {
-    $navi_datas = get_shop_navigation_data(true, $it['ca_id']);
-    $ca_ids = array(
-        'ca_id' => substr($it['ca_id'],0,2),
-        'ca_id2' => substr($it['ca_id'],0,4),
-        'ca_id3' => substr($it['ca_id'],0,6)
-        );
-}
+$is_item_view = (isset($it_id, $it['it_id']) && $it_id === $it['it_id']);
+$navigation_ca_id = $is_item_view ? $it['ca_id'] : $ca_id;
+$navi_datas = $navigation_ca_id ? get_shop_navigation_data(true, $navigation_ca_id) : array();
 
 $location_class = array();
 if($is_item_view){
@@ -27,7 +12,7 @@ if($is_item_view){
 	$location_class[] = 'is_list is_right';    // view_location는 리스트 말고 상품보기에서만 표시
 }
 
-// add_stylesheet('css 구문', 출력순서); 숫자가 작을 수록 먼저 출력됨
+// add_stylesheet('css 구문', 출력순서);
 add_stylesheet('<link rel="stylesheet" href="'.G5_SHOP_CSS_URL.'/style.css">', 0);
 add_javascript('<script src="'.G5_JS_URL.'/shop.category.navigation.js"></script>', 10);
 ?>
@@ -37,26 +22,14 @@ add_javascript('<script src="'.G5_JS_URL.'/shop.category.navigation.js"></script
     <i class="dividing-line fa fa-angle-right" aria-hidden="true"></i>
     <?php if ( is_array($navi_datas) && $navi_datas ){ ?>
 
-        <?php if( isset($navi_datas[0]) && $navi_datas[0] ){ ?>
-        <select class="shop_hover_selectbox category1">
-            <?php foreach((array) $navi_datas[0] as $data ){ ?>
-                <option value="<?php echo $data['ca_id']; ?>" data-url="<?php echo $data['url']; ?>" <?php if($ca_ids['ca_id'] === $data['ca_id']) echo 'selected'; ?>><?php echo $data['ca_name']; ?></option>
-            <?php } ?>
-        </select>
-        <?php } ?>
-        <?php if( isset($navi_datas[1]) && $navi_datas[1] ){ ?>
+        <?php foreach ($navi_datas as $depth => $categories) {
+            $selected_ca_id = substr($navigation_ca_id, 0, ($depth + 1) * 2);
+            if ($depth > 0) { ?>
         <i class="dividing-line fa fa-angle-right" aria-hidden="true"></i>
-        <select class="shop_hover_selectbox category2">
-            <?php foreach((array) $navi_datas[1] as $data ){ ?>
-                <option value="<?php echo $data['ca_id']; ?>" data-url="<?php echo $data['url']; ?>" <?php if($ca_ids['ca_id2'] === $data['ca_id']) echo 'selected'; ?>><?php echo $data['ca_name']; ?></option>
-            <?php } ?>
-        </select>
         <?php } ?>
-        <?php if( isset($navi_datas[2]) && $navi_datas[2] ){ ?>
-        <i class="dividing-line fa fa-angle-right" aria-hidden="true"></i>
-        <select class="shop_hover_selectbox category3">
-            <?php foreach((array) $navi_datas[2] as $data ){ ?>
-                <option value="<?php echo $data['ca_id']; ?>" data-url="<?php echo $data['url']; ?>" <?php if($ca_ids['ca_id3'] === $data['ca_id']) echo 'selected'; ?>><?php echo $data['ca_name']; ?></option>
+        <select class="shop_hover_selectbox category<?php echo $depth + 1; ?>" aria-label="<?php echo $depth + 1; ?>단계 분류">
+            <?php foreach ($categories as $data) { ?>
+            <option value="<?php echo $data['ca_id']; ?>" data-url="<?php echo $data['url']; ?>"<?php if ($selected_ca_id === $data['ca_id']) echo ' selected'; ?>><?php echo get_text($data['ca_name']); ?></option>
             <?php } ?>
         </select>
         <?php } ?>
diff --git a/tests/shop_category_layout.js b/tests/shop_category_layout.js
new file mode 100644
index 000000000..541c09d1e
--- /dev/null
+++ b/tests/shop_category_layout.js
@@ -0,0 +1,44 @@
+// 실행: NODE_PATH=<Playwright 경로>/node_modules CHROME_PATH=<Chromium 실행 파일> node tests/shop_category_layout.js
+const fs = require('fs');
+const path = require('path');
+const assert = require('assert');
+const {execFileSync} = require('child_process');
+const {chromium} = require('playwright');
+const root = path.dirname(__dirname);
+const read = file => fs.readFileSync(path.join(root, file), 'utf8');
+const fixtures = JSON.parse(execFileSync('php', [path.join(__dirname, 'shop_category_navigation.php'), '--json'], {encoding:'utf8'}));
+(async () => {
+    const browser = await chromium.launch({headless:true, ...(process.env.CHROME_PATH ? {executablePath:process.env.CHROME_PATH} : {}), args:['--no-sandbox']});
+    try {
+        for (const skin of ['skin/shop/basic', 'theme/basic/skin/shop/basic']) {
+            for (const view of ['list', 'item']) {
+                const page = await browser.newPage({viewport:{width:1920, height:1080}});
+                let baseline;
+                for (const id of ['10', '101010', '10101010', '1010101010']) {
+                    let html = fixtures[skin][id].replace(/<script>[\s\S]*?<\/script>/g, '');
+                    if (view === 'list') html = html.replace('view_location', 'is_list is_right');
+                    await page.setContent('<style>'+read(skin.startsWith('theme/') ? 'theme/basic/css/default_shop.css' : 'css/default_shop.css')+'\n'+read(skin+'/style.css')+'</style><div id="container"><div class="shop-content"><div id="wrapper_title">상품리스트</div><div class="sct_admin"><a>분류 관리</a></div><div id="sct">'+html+'<div id="sct_sortlst">상품 정렬</div></div></div></div>');
+                    await page.addScriptTag({content:read('js/jquery-1.12.4.min.js')});
+                    await page.addScriptTag({content:read('js/shop.category.navigation.js')});
+                    await page.evaluate(() => new Promise(resolve => jQuery(() => {
+                        jQuery('select.shop_hover_selectbox').shop_select_to_html();
+                        resolve();
+                    })));
+                    const layout = await page.evaluate(() => {
+                        const nav = document.getElementById('sct_location');
+                        const rect = nav.getBoundingClientRect();
+                        return {top:rect.top, height:rect.height, position:getComputedStyle(nav).position,
+                            menuTop:document.getElementById('sct_ct_1').getBoundingClientRect().top,
+                            sortTop:document.getElementById('sct_sortlst').getBoundingClientRect().top};
+                    });
+                    if (!baseline) baseline = layout;
+                    assert.deepStrictEqual(layout, baseline, skin+' '+view+' '+id+' 단계 변경 시 레이아웃 유지');
+                    assert.strictEqual(await page.locator('.shop_select_to_html').count(), id.length / 2);
+                    assert.strictEqual(await page.locator('#sct_ct_1 ul').count(), 1);
+                }
+                await page.close();
+            }
+        }
+        console.log('PC·basic 테마 목록/상세: 1·3·4·5단계 breadcrumb 위치·높이와 메뉴·정렬 영역 위치 동일');
+    } finally { await browser.close(); }
+})().catch(error => { console.error(error); process.exitCode = 1; });
diff --git a/tests/shop_category_navigation.php b/tests/shop_category_navigation.php
new file mode 100644
index 000000000..04fc62452
--- /dev/null
+++ b/tests/shop_category_navigation.php
@@ -0,0 +1,79 @@
+<?php
+// 실행: php tests/shop_category_navigation.php [--json]
+// DB 대신 분류 조회 대역을 사용하여 실제 공통 함수와 스킨을 실행한다.
+define('_GNUBOARD_', true);
+define('G5_SHOP_CSS_URL', '/css');
+define('G5_SHOP_SKIN_URL', '/skin');
+define('G5_SHOP_URL', '/shop');
+define('G5_JS_URL', '/js');
+$g5 = array('g5_shop_category_table'=>'categories', 'g5_shop_item_table'=>'items', 'title'=>'분류');
+$fixture_ids = array('10','20','1010','1020','101010','101020','10101010','10101020','1010101010','1010101020');
+function run_replace($name, $data, $cache) { return $data; }
+function shop_category_url($id) { return '/shop/list.php?ca_id='.$id; }
+function get_text($text) { return htmlspecialchars($text, ENT_QUOTES, 'UTF-8'); }
+function add_stylesheet($html, $priority) {}
+function add_javascript($html, $priority) {}
+function sql_query($sql) {
+    global $fixture_ids;
+    preg_match("/ca_id like '([^']*)%'/", $sql, $prefix);
+    preg_match("/length\(ca_id\) = '?([0-9]+)/", $sql, $length);
+    $result = (object)array('rows'=>array(), 'index'=>0);
+    foreach ($fixture_ids as $id) {
+        if ((!isset($prefix[1]) || strpos($id, $prefix[1]) === 0) && strlen($id) == $length[1]) {
+            $result->rows[] = array('ca_id'=>$id, 'ca_name'=>'분류 '.$id);
+        }
+    }
+    return $result;
+}
+function sql_fetch_array($result) { return isset($result->rows[$result->index]) ? $result->rows[$result->index++] : false; }
+function sql_fetch($sql) { return array('cnt'=>3); }
+function expect_category($condition, $message) { if (!$condition) throw new RuntimeException($message); }
+require dirname(__DIR__).'/lib/shop.data.lib.php';
+$artifacts = array();
+$cases = array(
+    '10'=>array(array('1010','1020')),
+    '20'=>array(array('10','20')),
+    '1010'=>array(array('101010','101020')),
+    '101010'=>array(array('10101010','10101020')),
+    '101020'=>array(array('101010','101020')),
+    '10101010'=>array(array('1010101010','1010101020')),
+    '10101020'=>array(array('10101010','10101020')),
+    '1010101010'=>array(array('1010101010','1010101020')),
+);
+foreach ($cases as $code=>$expected) {
+    $ca_id = (string)$code;
+    $groups = get_shop_category_menu_groups($ca_id);
+    $actual = array();
+    foreach ($groups as $group) {
+        $ids = array();
+        foreach ($group['categories'] as $row) $ids[] = $row['ca_id'];
+        $actual[] = $ids;
+    }
+    expect_category($actual === $expected, $ca_id.' 메뉴 단계');
+    foreach (array('skin/shop/basic', 'theme/basic/skin/shop/basic') as $skin) {
+        foreach (array(false, true) as $item_view) {
+            $it_id = $item_view ? 'item' : '';
+            $it = $item_view ? array('it_id'=>'item', 'ca_id'=>$ca_id) : array();
+            ob_start(); include dirname(__DIR__).'/'.$skin.'/navigation.skin.php'; $nav = ob_get_clean();
+            preg_match_all('/value="([0-9]+)"[^>]* selected/', $nav, $selected);
+            $path = array();
+            for ($depth=1; $depth<=strlen($ca_id)/2; $depth++) $path[] = substr($ca_id, 0, $depth*2);
+            expect_category($selected[1] === $path, $skin.' '.$ca_id.' breadcrumb 현재 경로');
+            $artifacts[$skin][$ca_id] = $nav;
+        }
+    }
+    foreach (array('skin/shop/basic', 'theme/basic/skin/shop/basic', 'mobile/skin/shop/basic', 'theme/basic/mobile/skin/shop/basic') as $skin) {
+        ob_start(); include dirname(__DIR__).'/'.$skin.'/listcategory.skin.php'; $menu = ob_get_clean();
+        preg_match_all('/href="\/shop\/list.php\?ca_id=([0-9]+)"/', $menu, $links);
+        $flattened = array(); foreach ($expected as $group) $flattened = array_merge($flattened, $group);
+        expect_category($links[1] === $flattened, $skin.' '.$ca_id.' 메뉴 링크');
+        preg_match_all('/aria-current="page" href="\/shop\/list.php\?ca_id=([0-9]+)"/', $menu, $selected);
+        expect_category($selected[1] === (in_array($ca_id, $flattened, true) ? array($ca_id) : array()), $skin.' 현재 메뉴 표시');
+        $artifacts[$skin][$ca_id] = (isset($artifacts[$skin][$ca_id]) ? $artifacts[$skin][$ca_id] : '').$menu;
+    }
+}
+// 5단계 전체 트리를 전역 메뉴에 추가하지 않았는지 확인한다.
+$tree = get_shop_category_array(true);
+expect_category(!isset($tree['10']['1010']['101010']['10101010']), '공통 분류 트리 호환성');
+if (isset($argv[1]) && $argv[1] === '--json') echo json_encode($artifacts);
+else echo "8개 분류 경로: PC·테마 breadcrumb 목록/상세 및 4개 스킨 메뉴·선택 상태 통과\n";
diff --git a/theme/basic/mobile/skin/shop/basic/listcategory.skin.php b/theme/basic/mobile/skin/shop/basic/listcategory.skin.php
index ddd995594..f966ab733 100644
--- a/theme/basic/mobile/skin/shop/basic/listcategory.skin.php
+++ b/theme/basic/mobile/skin/shop/basic/listcategory.skin.php
@@ -1,44 +1,25 @@
 <?php
-if (!defined("_GNUBOARD_")) exit; // 개별 페이지 접근 불가
+if (!defined('_GNUBOARD_')) exit;
 
-$str = '';
-$exists = false;
-
-$ca_id_len = strlen($ca_id);
-$len2 = $ca_id_len + 2;
-
-$sql = " select ca_id, ca_name from {$g5['g5_shop_category_table']} where ca_id like '$ca_id%' and length(ca_id) = $len2 and ca_use = '1' order by ca_order, ca_id ";
-$result = sql_query($sql);
-
-// 하위 분류가 없으면 현재 분류를 포함한 같은 단계의 사용 중인 분류를 표시한다.
-if (!sql_num_rows($result)) {
-    $parent_ca_id = substr($ca_id, 0, -2);
-    $sql = " select ca_id, ca_name from {$g5['g5_shop_category_table']} where ca_id like '$parent_ca_id%' and length(ca_id) = $ca_id_len and ca_use = '1' order by ca_order, ca_id ";
-    $result = sql_query($sql);
-}
-
-while ($row=sql_fetch_array($result)) {
-
-    $row2 = sql_fetch(" select count(*) as cnt from {$g5['g5_shop_item_table']} where (ca_id like '{$row['ca_id']}%' or ca_id2 like '{$row['ca_id']}%' or ca_id3 like '{$row['ca_id']}%') and it_use = '1'  ");
-
-    $current_attr = ($row['ca_id'] === $ca_id) ? ' class="sct_ct_here" aria-current="page"' : '';
-    $str .= '<li><a'.$current_attr.' href="'.shop_category_url($row['ca_id']).'">'.$row['ca_name'].' <span class="prd_cnt">'.$row2['cnt'].'</span></a></li>';
-    $exists = true;
-}
-
-if ($exists) {
-
-    // add_stylesheet('css 구문', 출력순서); 숫자가 작을 수록 먼저 출력됨
+$category_groups = get_shop_category_menu_groups($ca_id);
+if ($category_groups) {
     add_stylesheet('<link rel="stylesheet" href="'.G5_SHOP_CSS_URL.'/style.css">', 0);
 ?>
-
-<!-- 상품분류 1 시작 { -->
 <aside id="sct_ct_1" class="sct_ct">
     <h2>현재 상품 분류와 관련된 분류</h2>
-    <ul>
-        <?php echo $str; ?>
+    <?php foreach ($category_groups as $category_group) { ?>
+    <ul aria-label="<?php echo $category_group['label']; ?>">
+        <?php foreach ($category_group['categories'] as $row) {
+            $row2 = sql_fetch(" select count(*) as cnt from {$g5['g5_shop_item_table']} where (ca_id like '{$row['ca_id']}%' or ca_id2 like '{$row['ca_id']}%' or ca_id3 like '{$row['ca_id']}%') and it_use = '1' ");
+            $current_attr = '';
+            if ($row['ca_id'] === $ca_id) {
+                $current_attr = ' class="sct_ct_here" aria-current="page"';
+            } elseif (strpos($ca_id, $row['ca_id']) === 0) {
+                $current_attr = ' class="sct_ct_here sct_ct_parent"';
+            }
+            echo '<li><a'.$current_attr.' href="'.shop_category_url($row['ca_id']).'">'.get_text($row['ca_name']).' <span class="prd_cnt">'.$row2['cnt'].'</span></a></li>';
+        } ?>
     </ul>
+    <?php } ?>
 </aside>
-<!-- } 상품분류 1 끝 -->
-
-<?php }
\ No newline at end of file
+<?php }
diff --git a/theme/basic/skin/shop/basic/listcategory.skin.php b/theme/basic/skin/shop/basic/listcategory.skin.php
index 6f1ad0d40..91f7393ec 100644
--- a/theme/basic/skin/shop/basic/listcategory.skin.php
+++ b/theme/basic/skin/shop/basic/listcategory.skin.php
@@ -1,44 +1,25 @@
 <?php
-if (!defined("_GNUBOARD_")) exit; // 개별 페이지 접근 불가
+if (!defined('_GNUBOARD_')) exit;
 
-$str = '';
-$exists = false;
-
-$ca_id_len = strlen($ca_id);
-$len2 = $ca_id_len + 2;
-
-$sql = " select ca_id, ca_name from {$g5['g5_shop_category_table']} where ca_id like '$ca_id%' and length(ca_id) = $len2 and ca_use = '1' order by ca_order, ca_id ";
-$result = sql_query($sql);
-
-// 하위 분류가 없으면 현재 분류를 포함한 같은 단계의 사용 중인 분류를 표시한다.
-if (!sql_num_rows($result)) {
-    $parent_ca_id = substr($ca_id, 0, -2);
-    $sql = " select ca_id, ca_name from {$g5['g5_shop_category_table']} where ca_id like '$parent_ca_id%' and length(ca_id) = $ca_id_len and ca_use = '1' order by ca_order, ca_id ";
-    $result = sql_query($sql);
-}
-
-while ($row=sql_fetch_array($result)) {
-
-    $row2 = sql_fetch(" select count(*) as cnt from {$g5['g5_shop_item_table']} where (ca_id like '{$row['ca_id']}%' or ca_id2 like '{$row['ca_id']}%' or ca_id3 like '{$row['ca_id']}%') and it_use = '1'  ");
-
-    $current_attr = ($row['ca_id'] === $ca_id) ? ' class="sct_ct_here" aria-current="page"' : '';
-    $str .= '<li><a'.$current_attr.' href="'.shop_category_url($row['ca_id']).'">'.$row['ca_name'].' ('.$row2['cnt'].')</a></li>';
-    $exists = true;
-}
-
-if ($exists) {
-
-    // add_stylesheet('css 구문', 출력순서); 숫자가 작을 수록 먼저 출력됨
+$category_groups = get_shop_category_menu_groups($ca_id);
+if ($category_groups) {
     add_stylesheet('<link rel="stylesheet" href="'.G5_SHOP_SKIN_URL.'/style.css">', 0);
 ?>
-
-<!-- 상품분류 1 시작 { -->
 <aside id="sct_ct_1" class="sct_ct">
     <h2>현재 상품 분류와 관련된 분류</h2>
-    <ul>
-        <?php echo $str; ?>
+    <?php foreach ($category_groups as $category_group) { ?>
+    <ul aria-label="<?php echo $category_group['label']; ?>">
+        <?php foreach ($category_group['categories'] as $row) {
+            $row2 = sql_fetch(" select count(*) as cnt from {$g5['g5_shop_item_table']} where (ca_id like '{$row['ca_id']}%' or ca_id2 like '{$row['ca_id']}%' or ca_id3 like '{$row['ca_id']}%') and it_use = '1' ");
+            $current_attr = '';
+            if ($row['ca_id'] === $ca_id) {
+                $current_attr = ' class="sct_ct_here" aria-current="page"';
+            } elseif (strpos($ca_id, $row['ca_id']) === 0) {
+                $current_attr = ' class="sct_ct_here sct_ct_parent"';
+            }
+            echo '<li><a'.$current_attr.' href="'.shop_category_url($row['ca_id']).'">'.get_text($row['ca_name']).' ('.$row2['cnt'].')</a></li>';
+        } ?>
     </ul>
+    <?php } ?>
 </aside>
-<!-- } 상품분류 1 끝 -->
-
-<?php }
\ No newline at end of file
+<?php }
diff --git a/theme/basic/skin/shop/basic/navigation.skin.php b/theme/basic/skin/shop/basic/navigation.skin.php
index 0d830144d..fa99d54ad 100644
--- a/theme/basic/skin/shop/basic/navigation.skin.php
+++ b/theme/basic/skin/shop/basic/navigation.skin.php
@@ -1,24 +1,9 @@
 <?php
 if (!defined("_GNUBOARD_")) exit; // 개별 페이지 접근 불가
 
-$navi_datas = $ca_ids = array();
-$is_item_view = (isset($it_id) && isset($it) && isset($it['it_id']) && $it_id === $it['it_id']) ? true : false;
-
-if( !$is_item_view && $ca_id ){
-    $navi_datas = get_shop_navigation_data(true, $ca_id);
-    $ca_ids = array(
-        'ca_id' => substr($ca_id,0,2),
-        'ca_id2' => substr($ca_id,0,4),
-        'ca_id3' => substr($ca_id,0,6),
-        );
-} else if( $is_item_view && isset($it) && is_array($it) ) {
-    $navi_datas = get_shop_navigation_data(true, $it['ca_id']);
-    $ca_ids = array(
-        'ca_id' => substr($it['ca_id'],0,2),
-        'ca_id2' => substr($it['ca_id'],0,4),
-        'ca_id3' => substr($it['ca_id'],0,6)
-        );
-}
+$is_item_view = (isset($it_id, $it['it_id']) && $it_id === $it['it_id']);
+$navigation_ca_id = $is_item_view ? $it['ca_id'] : $ca_id;
+$navi_datas = $navigation_ca_id ? get_shop_navigation_data(true, $navigation_ca_id) : array();
 
 $location_class = array();
 if($is_item_view){
@@ -27,7 +12,7 @@ if($is_item_view){
 	$location_class[] = 'is_list is_right';    // view_location는 리스트 말고 상품보기에서만 표시
 }
 
-// add_stylesheet('css 구문', 출력순서); 숫자가 작을 수록 먼저 출력됨
+// add_stylesheet('css 구문', 출력순서);
 add_stylesheet('<link rel="stylesheet" href="'.G5_SHOP_CSS_URL.'/style.css">', 0);
 add_javascript('<script src="'.G5_JS_URL.'/shop.category.navigation.js"></script>', 10);
 ?>
@@ -37,26 +22,14 @@ add_javascript('<script src="'.G5_JS_URL.'/shop.category.navigation.js"></script
     <i class="dividing-line fa fa-angle-right" aria-hidden="true"></i>
     <?php if ( is_array($navi_datas) && $navi_datas ){ ?>
 
-        <?php if( isset($navi_datas[0]) && $navi_datas[0] ){ ?>
-        <select class="shop_hover_selectbox category1">
-            <?php foreach((array) $navi_datas[0] as $data ){ ?>
-                <option value="<?php echo $data['ca_id']; ?>" data-url="<?php echo $data['url']; ?>" <?php if($ca_ids['ca_id'] === $data['ca_id']) echo 'selected'; ?>><?php echo $data['ca_name']; ?></option>
-            <?php } ?>
-        </select>
-        <?php } ?>
-        <?php if( isset($navi_datas[1]) && $navi_datas[1] ){ ?>
+        <?php foreach ($navi_datas as $depth => $categories) {
+            $selected_ca_id = substr($navigation_ca_id, 0, ($depth + 1) * 2);
+            if ($depth > 0) { ?>
         <i class="dividing-line fa fa-angle-right" aria-hidden="true"></i>
-        <select class="shop_hover_selectbox category2">
-            <?php foreach((array) $navi_datas[1] as $data ){ ?>
-                <option value="<?php echo $data['ca_id']; ?>" data-url="<?php echo $data['url']; ?>" <?php if($ca_ids['ca_id2'] === $data['ca_id']) echo 'selected'; ?>><?php echo $data['ca_name']; ?></option>
-            <?php } ?>
-        </select>
         <?php } ?>
-        <?php if( isset($navi_datas[2]) && $navi_datas[2] ){ ?>
-        <i class="dividing-line fa fa-angle-right" aria-hidden="true"></i>
-        <select class="shop_hover_selectbox category3">
-            <?php foreach((array) $navi_datas[2] as $data ){ ?>
-                <option value="<?php echo $data['ca_id']; ?>" data-url="<?php echo $data['url']; ?>" <?php if($ca_ids['ca_id3'] === $data['ca_id']) echo 'selected'; ?>><?php echo $data['ca_name']; ?></option>
+        <select class="shop_hover_selectbox category<?php echo $depth + 1; ?>" aria-label="<?php echo $depth + 1; ?>단계 분류">
+            <?php foreach ($categories as $data) { ?>
+            <option value="<?php echo $data['ca_id']; ?>" data-url="<?php echo $data['url']; ?>"<?php if ($selected_ca_id === $data['ca_id']) echo ' selected'; ?>><?php echo get_text($data['ca_name']); ?></option>
             <?php } ?>
         </select>
         <?php } ?>
diff --git a/version.php b/version.php
index 95f6f19a9..c5d39cbd6 100644
--- a/version.php
+++ b/version.php
@@ -2,7 +2,7 @@
 if (!defined('_GNUBOARD_')) exit; // 개별 페이지 접근 불가
 
 define('G5_VERSION', '그누보드5');
-define('G5_GNUBOARD_VER', '5.6.39');
+define('G5_GNUBOARD_VER', '5.6.391');
 // 그누보드5.4.5.5 버전과 영카트5.4.5.5.1 버전을 합쳐서 그누보드5.4.6 버전에서 시작함 (kagla-210617)
 // G5_YOUNGCART_VER 이 상수를 사용하는 곳이 있으므로 주석 처리 해제함
 // 그누보드5.4.6 이상 버전 부터는 영카트를 그누보드에 포함하여 배포하므로 영카트5의 버전은 의미가 없습니다.