diff --git a/.jules/sentinel.md b/.jules/sentinel.md
index e795cb9d..4e408e73 100644
--- a/.jules/sentinel.md
+++ b/.jules/sentinel.md
@@ -32,3 +32,7 @@
 **Vulnerability:** The document hashing routine in `DefaultDocumentConversionService` processed file streams without enforcing any maximum size limit on the bytes read. An attacker could exploit this by uploading a maliciously large stream (or exploiting a compression bomb if unzipping), exhausting system memory, CPU, or disk space (DoS).
 **Learning:** Checking the declared file size (e.g., `file.getSize()`) in initial validation is not always sufficient if the input stream itself can be spoofed or dynamically expanded during reading. The actual bytes read must be verified against bounds continuously.
 **Prevention:** Always enforce a strict, configurable size limit (e.g., `ConversionProperties.maxUploadSizeBytes`) within the `while` loop that reads from untrusted input streams. Track `totalRead` and throw an exception immediately if the limit is exceeded.
+## 2026-07-25 - 관리자 엔드포인트 인증/인가 누락 해결
+**Vulnerability:** `AdminController`의 엔드포인트(`getAllJobs`, `deleteJob`, `retryDeadLettered`)에 인증 및 인가 검사가 누락되어 모든 사용자가 접근 가능한 취약점이 발견되었습니다.
+**Learning:** 새로운 컨트롤러나 엔드포인트를 추가할 때, 스프링 시큐리티 어노테이션이 아닌 수동으로 `TenantAccessService`를 주입하여 인증 및 인가를 적용해야 하는 프로젝트의 보안 아키텍처 특성 상 누락되기 쉽습니다.
+**Prevention:** 모든 새로운 컨트롤러 및 민감한 엔드포인트 생성 시 `TenantAccessService.require(headers, ...)` 호출이 포함되어 있는지 기본적으로 검증하는 리뷰 절차가 필요합니다.
diff --git a/src/main/java/com/clearfolio/viewer/auth/TenantPermissions.java b/src/main/java/com/clearfolio/viewer/auth/TenantPermissions.java
index ced5e6a3..cf84895c 100644
--- a/src/main/java/com/clearfolio/viewer/auth/TenantPermissions.java
+++ b/src/main/java/com/clearfolio/viewer/auth/TenantPermissions.java
@@ -50,6 +50,16 @@ public final class TenantPermissions {
      */
     public static final String ANALYTICS_READ = "analytics:read";
 
+    /**
+     * Permission required to read admin endpoints.
+     */
+    public static final String ADMIN_READ = "admin:read";
+
+    /**
+     * Permission required to write/modify via admin endpoints.
+     */
+    public static final String ADMIN_WRITE = "admin:write";
+
     private TenantPermissions() {
     }
 }
diff --git a/src/main/java/com/clearfolio/viewer/controller/AdminController.java b/src/main/java/com/clearfolio/viewer/controller/AdminController.java
index 412d4eb8..c66a30b4 100644
--- a/src/main/java/com/clearfolio/viewer/controller/AdminController.java
+++ b/src/main/java/com/clearfolio/viewer/controller/AdminController.java
@@ -4,17 +4,21 @@
 import java.util.List;
 import java.util.UUID;
 
+import org.springframework.http.HttpHeaders;
 import org.springframework.http.HttpStatus;
 import org.springframework.http.ResponseEntity;
 import org.springframework.web.bind.annotation.DeleteMapping;
 import org.springframework.web.bind.annotation.GetMapping;
 import org.springframework.web.bind.annotation.PathVariable;
 import org.springframework.web.bind.annotation.PostMapping;
+import org.springframework.web.bind.annotation.RequestHeader;
 import org.springframework.web.bind.annotation.RequestParam;
 import org.springframework.web.bind.annotation.RestController;
 import org.springframework.web.server.ResponseStatusException;
 
 import com.clearfolio.viewer.api.AdminJobListResponse;
+import com.clearfolio.viewer.auth.TenantAccessService;
+import com.clearfolio.viewer.auth.TenantPermissions;
 import com.clearfolio.viewer.model.ConversionJob;
 import com.clearfolio.viewer.service.DocumentConversionService;
 import com.clearfolio.viewer.service.RetryDeadLetterResult;
@@ -25,25 +29,40 @@
 @RestController
 public class AdminController {
 
+        /**
+     * Document conversion service.
+     */
     private final DocumentConversionService conversionService;
+        /**
+     * Tenant access service.
+     */
+    private final TenantAccessService tenantAccessService;
 
     /**
      * Creates a controller for admin operations.
      *
-     * @param conversionService conversion service
+     * @param injectedConversionService conversion service
+     * @param injectedTenantAccessService tenant access service
      */
-    public AdminController(DocumentConversionService conversionService) {
-        this.conversionService = conversionService;
+    public AdminController(
+            final DocumentConversionService injectedConversionService,
+            final TenantAccessService injectedTenantAccessService) {
+        this.conversionService = injectedConversionService;
+        this.tenantAccessService = injectedTenantAccessService;
     }
 
     /**
      * Retrieves all conversion jobs, optionally filtered by dead-letter status.
      *
      * @param deadLettered optional filter for dead-lettered jobs
+     * @param headers request headers
      * @return list of conversion jobs
      */
     @GetMapping("/api/v1/admin/convert/jobs")
-    public AdminJobListResponse getAllJobs(@RequestParam(required = false) Boolean deadLettered) {
+    public AdminJobListResponse getAllJobs(
+            @RequestParam(required = false) final Boolean deadLettered,
+            @RequestHeader final HttpHeaders headers) {
+        tenantAccessService.require(headers, TenantPermissions.ADMIN_READ);
         Iterable<ConversionJob> allJobs = conversionService.getAllJobs();
 
         if (deadLettered == null) {
@@ -63,10 +82,14 @@ public AdminJobListResponse getAllJobs(@RequestParam(required = false) Boolean d
      * Deletes a conversion job.
      *
      * @param jobId conversion job identifier
+     * @param headers request headers
      * @return no content on success
      */
     @DeleteMapping("/api/v1/admin/convert/jobs/{jobId}")
-    public ResponseEntity<Void> deleteJob(@PathVariable UUID jobId) {
+    public ResponseEntity<Void> deleteJob(
+            @PathVariable final UUID jobId,
+            @RequestHeader final HttpHeaders headers) {
+        tenantAccessService.require(headers, TenantPermissions.ADMIN_WRITE);
         conversionService.deleteJob(jobId);
         return ResponseEntity.noContent().build();
     }
@@ -75,16 +98,23 @@ public ResponseEntity<Void> deleteJob(@PathVariable UUID jobId) {
      * Retries a dead-lettered conversion job.
      *
      * @param jobId conversion job identifier
+     * @param headers request headers
      * @return accepted response on success
      */
     @PostMapping("/api/v1/admin/convert/jobs/{jobId}/retry")
-    public ResponseEntity<Void> retryDeadLettered(@PathVariable UUID jobId) {
-        RetryDeadLetterResult result = conversionService.retryDeadLettered(jobId, "admin");
+    public ResponseEntity<Void> retryDeadLettered(
+            @PathVariable final UUID jobId,
+            @RequestHeader final HttpHeaders headers) {
+        tenantAccessService.require(headers, TenantPermissions.ADMIN_WRITE);
+        RetryDeadLetterResult result = conversionService
+                .retryDeadLettered(jobId, "admin");
         if (result == RetryDeadLetterResult.NOT_FOUND) {
-            throw new ResponseStatusException(HttpStatus.NOT_FOUND, "job not found");
+            throw new ResponseStatusException(
+                    HttpStatus.NOT_FOUND, "job not found");
         }
         if (result == RetryDeadLetterResult.NOT_ELIGIBLE) {
-            throw new ResponseStatusException(HttpStatus.CONFLICT, "job is not eligible for retry");
+            throw new ResponseStatusException(
+                    HttpStatus.CONFLICT, "job is not eligible for retry");
         }
         return ResponseEntity.accepted().build();
     }
diff --git a/src/test/java/com/clearfolio/viewer/controller/AdminControllerTest.java b/src/test/java/com/clearfolio/viewer/controller/AdminControllerTest.java
index ad63a801..90437dda 100644
--- a/src/test/java/com/clearfolio/viewer/controller/AdminControllerTest.java
+++ b/src/test/java/com/clearfolio/viewer/controller/AdminControllerTest.java
@@ -1,6 +1,8 @@
 package com.clearfolio.viewer.controller;
 
 import static org.mockito.Mockito.mock;
+import static org.mockito.ArgumentMatchers.any;
+import static org.mockito.ArgumentMatchers.eq;
 import static org.mockito.Mockito.when;
 
 import java.util.Arrays;
@@ -8,8 +10,12 @@
 
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
+import org.springframework.http.HttpHeaders;
 import org.springframework.test.web.reactive.server.WebTestClient;
 
+import com.clearfolio.viewer.auth.TenantAccessService;
+import com.clearfolio.viewer.auth.TenantContext;
+import com.clearfolio.viewer.auth.TenantPermissions;
 import com.clearfolio.viewer.model.ConversionJob;
 import com.clearfolio.viewer.service.DocumentConversionService;
 import com.clearfolio.viewer.service.RetryDeadLetterResult;
@@ -17,13 +23,21 @@
 class AdminControllerTest {
 
     private DocumentConversionService conversionService;
+    private TenantAccessService tenantAccessService;
     private WebTestClient webTestClient;
     private AdminController controller;
+    private TenantContext tenantContext;
 
     @BeforeEach
     void setUp() {
         conversionService = mock(DocumentConversionService.class);
-        controller = new AdminController(conversionService);
+        tenantAccessService = mock(TenantAccessService.class);
+        tenantContext = mock(TenantContext.class);
+
+        // By default, allow everything
+        when(tenantAccessService.require(any(HttpHeaders.class), any(String.class))).thenReturn(tenantContext);
+
+        controller = new AdminController(conversionService, tenantAccessService);
         webTestClient = WebTestClient.bindToController(controller)
                 .controllerAdvice(new ApiExceptionHandler())
                 .build();