diff --git a/src/app/api/auth/session/route.ts b/src/app/api/auth/session/route.ts
index 534fbee..ac07ed9 100644
--- a/src/app/api/auth/session/route.ts
+++ b/src/app/api/auth/session/route.ts
@@ -61,15 +61,27 @@ export async function POST(req: Request) {
     });
     isAdmin = !!hasAdmin;
   }
+  // 추가 안전장치: 사용자 레코드의 authLevel이 ADMIN이면 관리자 취급
+  if (!isAdmin && user.authLevel === "ADMIN") {
+    isAdmin = true;
+  }
 
   const res = NextResponse.json({ ok: true, user: { userId: user.userId, nickname: user.nickname } });
+  // HTTPS 요청에서만 Secure 속성 부여 (HTTP 환경에서는 생략하여 로컬 start에서도 동작)
+  let secureAttr = "";
+  try {
+    const isHttps = new URL(req.url).protocol === "https:";
+    secureAttr = isHttps ? "; Secure" : "";
+  } catch {
+    secureAttr = "";
+  }
   res.headers.append(
     "Set-Cookie",
-    `uid=${encodeURIComponent(user.userId)}; Path=/; HttpOnly; SameSite=Lax`
+    `uid=${encodeURIComponent(user.userId)}; Path=/; HttpOnly; SameSite=Lax${secureAttr}`
   );
   res.headers.append(
     "Set-Cookie",
-    `isAdmin=${isAdmin ? "1" : "0"}; Path=/; HttpOnly; SameSite=Lax`
+    `isAdmin=${isAdmin ? "1" : "0"}; Path=/; HttpOnly; SameSite=Lax${secureAttr}`
   );
   return res;
 }
diff --git a/src/app/api/boards/route.ts b/src/app/api/boards/route.ts
index 64bfb48..783292b 100644
--- a/src/app/api/boards/route.ts
+++ b/src/app/api/boards/route.ts
@@ -4,7 +4,7 @@ import prisma from "@/lib/prisma";
 export async function GET(req: Request) {
   const { searchParams } = new URL(req.url);
   const category = searchParams.get("category"); // slug or id
-  const where: any = {};
+  const where: any = { status: "active" };
   if (category) {
     if (category.length === 25 || category.length === 24) {
       where.categoryId = category;
diff --git a/src/app/boards/[id]/page.tsx b/src/app/boards/[id]/page.tsx
index d044ed7..5c1933d 100644
--- a/src/app/boards/[id]/page.tsx
+++ b/src/app/boards/[id]/page.tsx
@@ -4,6 +4,7 @@ import Link from "next/link";
 import { BoardToolbar } from "@/app/components/BoardToolbar";
 import { headers } from "next/headers";
 import prisma from "@/lib/prisma";
+import { notFound } from "next/navigation";
 import { UserAvatar } from "@/app/components/UserAvatar";
 import { RankIcon1st } from "@/app/components/RankIcon1st";
 import { RankIcon2nd } from "@/app/components/RankIcon2nd";
@@ -33,7 +34,10 @@ export default async function BoardDetail({ params, searchParams }: { params: an
   const res = await fetch(new URL("/api/boards", base).toString(), { cache: "no-store" });
   const { boards } = await res.json();
   const board = (boards || []).find((b: any) => b.slug === idOrSlug || b.id === idOrSlug);
-  const id = board?.id as string;
+  if (!board) {
+    return notFound();
+  }
+  const id = board.id as string;
   const siblingBoards = (boards || []).filter((b: any) => b.category?.id && b.category.id === board?.category?.id);
   const categoryName = board?.category?.name ?? "";
   // 메인배너 표시 설정
diff --git a/src/app/components/BoardPanelClient.tsx b/src/app/components/BoardPanelClient.tsx
index 022e18c..9a30340 100644
--- a/src/app/components/BoardPanelClient.tsx
+++ b/src/app/components/BoardPanelClient.tsx
@@ -1,6 +1,6 @@
 "use client";
 
-import { useState } from "react";
+import { useEffect, useState } from "react";
 import Link from "next/link";
 import { RankIcon1st } from "./RankIcon1st";
 import { RankIcon2nd } from "./RankIcon2nd";
@@ -52,6 +52,23 @@ export function BoardPanelClient({
 }) {
   const [selectedBoardId, setSelectedBoardId] = useState(initialBoardId);
 
+  // 데이터가 비어있을 때 안전 처리
+  if (!boardsData || boardsData.length === 0) {
+    return (
+      <div className="h-full min-h-0 flex items-center justify-center rounded-xl bg-white text-sm text-neutral-500">
+        선택된 게시판이 없습니다.
+      </div>
+    );
+  }
+
+  // 선택된 보드가 목록에 없으면 첫 번째 보드로 동기화
+  useEffect(() => {
+    const exists = boardsData.some((bd) => bd.board.id === selectedBoardId);
+    if (!exists) {
+      setSelectedBoardId(boardsData[0].board.id);
+    }
+  }, [boardsData, selectedBoardId]);
+
   // 선택된 게시판 데이터 찾기
   const selectedBoardData = boardsData.find(bd => bd.board.id === selectedBoardId) || boardsData[0];
   const { board, categoryName, siblingBoards } = selectedBoardData;
diff --git a/src/app/page.tsx b/src/app/page.tsx
index f6a1f13..cb12fef 100644
--- a/src/app/page.tsx
+++ b/src/app/page.tsx
@@ -77,7 +77,7 @@ export default async function Home({ searchParams }: { searchParams: Promise<{ s
   // 보드 메타데이터 (메인뷰 타입 포함)
   const boardsMeta = visibleBoardIds.length
     ? await prisma.board.findMany({
-        where: { id: { in: visibleBoardIds } },
+        where: { id: { in: visibleBoardIds }, status: "active" },
         select: {
           id: true,
           name: true,
@@ -116,14 +116,26 @@ export default async function Home({ searchParams }: { searchParams: Promise<{ s
   // 게시판 패널 데이터 수집 함수 (모든 sibling boards 포함)
   const prepareBoardPanelData = async (board: { id: string; name: string; slug: string; categoryId: string | null; categoryName: string; mainTypeKey?: string }) => {
     // 같은 카테고리의 소분류(게시판) 탭 목록
-    const siblingBoards = board.categoryId
+    let siblingBoards: any[] = board.categoryId
       ? await prisma.board.findMany({
-          where: { categoryId: board.categoryId },
+          where: { categoryId: board.categoryId, status: "active" },
           select: { id: true, name: true, slug: true, mainPageViewType: { select: { key: true } } },
           orderBy: [{ sortOrder: "asc" }, { name: "asc" }],
         })
       : [];
 
+    // 카테고리가 없거나 동료 게시판이 없을 때, 선택된 보드 단독 구성으로 대체
+    if (siblingBoards.length === 0) {
+      siblingBoards = [
+        {
+          id: board.id,
+          name: board.name,
+          slug: board.slug,
+          mainPageViewType: { key: board.mainTypeKey },
+        },
+      ];
+    }
+
     const boardsData = [];
     
     for (const sb of siblingBoards) {
diff --git a/src/middleware.ts b/src/middleware.ts
index 8a9dd54..08ebe9e 100644
--- a/src/middleware.ts
+++ b/src/middleware.ts
@@ -17,7 +17,8 @@ export async function middleware(req: NextRequest) {
   }
 
   // uid 쿠키가 있어도 실제 유저가 존재하지 않으면 비로그인으로 간주하고 쿠키 정리
-  let authenticated = false;
+  // 기본값은 쿠키 존재 여부 기준(네트워크 오류 시 과도한 로그아웃 방지)
+  let authenticated = !!uid;
   if (uid) {
     try {
       const verifyUrl = new URL("/api/auth/session", req.url);
@@ -30,9 +31,13 @@ export async function middleware(req: NextRequest) {
       if (verifyRes.ok) {
         const data = await verifyRes.json().catch(() => ({ ok: false }));
         authenticated = !!data?.ok;
+      } else {
+        // 검증 API가 200이 아니면 기존 판단 유지(일시적 오류 대비)
+        authenticated = !!uid;
       }
     } catch {
-      authenticated = false;
+      // 네트워크/런타임 오류 시 기존 판단 유지(쿠키 있으면 로그인 간주)
+      authenticated = !!uid;
     }
     // 유효하지 않은 uid 쿠키는 즉시 제거
     if (!authenticated) {