diff --git a/CHANGELOG.md b/CHANGELOG.md
index e8e8c980..49618d6d 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,8 @@
 ## [Unreleased]
 ### Added
+- **관리자 API 권한 검증 추가**
+  - `AdminController`의 전체 관리자 엔드포인트에 `TenantAccessService`를 통한 `ADMIN_READ` 및 `ADMIN_WRITE` 권한 검증 로직을 추가하여 인증 우회를 방지했습니다.
+
 - **UI UX 개선**: 'Details' 버튼 클릭 시, 작업 상세 정보 로드 중에 사용자가 명시적인 로딩 상태를 확인할 수 있도록 'Loading...' 텍스트와 비활성화 상태를 표시하도록 추가했습니다.
 
 # Changelog
diff --git a/src/main/java/com/clearfolio/viewer/auth/TenantPermissions.java b/src/main/java/com/clearfolio/viewer/auth/TenantPermissions.java
index ced5e6a3..7f805711 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 list all conversion jobs across tenants.
+     */
+    public static final String ADMIN_READ = "admin:read";
+
+    /**
+     * Permission required to modify or delete jobs globally.
+     */
+    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..f016de01 100644
--- a/src/main/java/com/clearfolio/viewer/controller/AdminController.java
+++ b/src/main/java/com/clearfolio/viewer/controller/AdminController.java
@@ -10,11 +10,15 @@
 import org.springframework.web.bind.annotation.GetMapping;
 import org.springframework.web.bind.annotation.PathVariable;
 import org.springframework.web.bind.annotation.PostMapping;
+import org.springframework.http.HttpHeaders;
+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;
@@ -26,24 +30,32 @@
 public class AdminController {
 
     private final DocumentConversionService conversionService;
+    private final TenantAccessService tenantAccessService;
 
     /**
      * Creates a controller for admin operations.
      *
      * @param conversionService conversion service
+     * @param tenantAccessService tenant access service
      */
-    public AdminController(DocumentConversionService conversionService) {
+    public AdminController(DocumentConversionService conversionService, TenantAccessService tenantAccessService) {
         this.conversionService = conversionService;
+        this.tenantAccessService = tenantAccessService;
     }
 
     /**
      * Retrieves all conversion jobs, optionally filtered by dead-letter status.
      *
      * @param deadLettered optional filter for dead-lettered jobs
+     * @param headers request headers carrying tenant claims
      * @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) Boolean deadLettered,
+            @RequestHeader HttpHeaders headers) {
+        tenantAccessService.require(headers, TenantPermissions.ADMIN_READ);
+
         Iterable<ConversionJob> allJobs = conversionService.getAllJobs();
 
         if (deadLettered == null) {
@@ -63,10 +75,15 @@ public AdminJobListResponse getAllJobs(@RequestParam(required = false) Boolean d
      * Deletes a conversion job.
      *
      * @param jobId conversion job identifier
+     * @param headers request headers carrying tenant claims
      * @return no content on success
      */
     @DeleteMapping("/api/v1/admin/convert/jobs/{jobId}")
-    public ResponseEntity<Void> deleteJob(@PathVariable UUID jobId) {
+    public ResponseEntity<Void> deleteJob(
+            @PathVariable UUID jobId,
+            @RequestHeader HttpHeaders headers) {
+        tenantAccessService.require(headers, TenantPermissions.ADMIN_WRITE);
+
         conversionService.deleteJob(jobId);
         return ResponseEntity.noContent().build();
     }
@@ -75,10 +92,15 @@ public ResponseEntity<Void> deleteJob(@PathVariable UUID jobId) {
      * Retries a dead-lettered conversion job.
      *
      * @param jobId conversion job identifier
+     * @param headers request headers carrying tenant claims
      * @return accepted response on success
      */
     @PostMapping("/api/v1/admin/convert/jobs/{jobId}/retry")
-    public ResponseEntity<Void> retryDeadLettered(@PathVariable UUID jobId) {
+    public ResponseEntity<Void> retryDeadLettered(
+            @PathVariable UUID jobId,
+            @RequestHeader 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");
diff --git a/src/test/java/com/clearfolio/viewer/controller/AdminControllerTest.java b/src/test/java/com/clearfolio/viewer/controller/AdminControllerTest.java
index ad63a801..fa4c7a1d 100644
--- a/src/test/java/com/clearfolio/viewer/controller/AdminControllerTest.java
+++ b/src/test/java/com/clearfolio/viewer/controller/AdminControllerTest.java
@@ -6,10 +6,16 @@
 import java.util.Arrays;
 import java.util.UUID;
 
+import static org.mockito.ArgumentMatchers.any;
+import static org.mockito.ArgumentMatchers.eq;
+
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
 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 +23,20 @@
 class AdminControllerTest {
 
     private DocumentConversionService conversionService;
+    private TenantAccessService tenantAccessService;
     private WebTestClient webTestClient;
     private AdminController controller;
 
     @BeforeEach
     void setUp() {
         conversionService = mock(DocumentConversionService.class);
-        controller = new AdminController(conversionService);
+        tenantAccessService = mock(TenantAccessService.class);
+
+        when(tenantAccessService.require(any(), any())).thenReturn(
+                new TenantContext("tenant-1", "user-1", java.util.Set.of())
+        );
+
+        controller = new AdminController(conversionService, tenantAccessService);
         webTestClient = WebTestClient.bindToController(controller)
                 .controllerAdvice(new ApiExceptionHandler())
                 .build();
@@ -37,6 +50,7 @@ void getAllJobsReturnsAllJobsWhenNoFilterProvided() {
 
         webTestClient.get()
                 .uri("/api/v1/admin/convert/jobs")
+                .header("X-Dummy", "dummy")
                 .exchange()
                 .expectStatus().isOk()
                 .expectBody()
@@ -55,6 +69,7 @@ void getAllJobsFiltersByDeadLetteredTrue() {
 
         webTestClient.get()
                 .uri("/api/v1/admin/convert/jobs?deadLettered=true")
+                .header("X-Dummy", "dummy")
                 .exchange()
                 .expectStatus().isOk()
                 .expectBody()
@@ -72,6 +87,7 @@ void getAllJobsFiltersByDeadLetteredFalse() {
 
         webTestClient.get()
                 .uri("/api/v1/admin/convert/jobs?deadLettered=false")
+                .header("X-Dummy", "dummy")
                 .exchange()
                 .expectStatus().isOk()
                 .expectBody()
@@ -85,6 +101,7 @@ void deleteJobReturnsNoContent() {
 
         webTestClient.delete()
                 .uri("/api/v1/admin/convert/jobs/" + jobId)
+                .header("X-Dummy", "dummy")
                 .exchange()
                 .expectStatus().isNoContent();
     }
@@ -96,6 +113,7 @@ void retryDeadLetteredReturnsAcceptedWhenAccepted() {
 
         webTestClient.post()
                 .uri("/api/v1/admin/convert/jobs/" + jobId + "/retry")
+                .header("X-Dummy", "dummy")
                 .exchange()
                 .expectStatus().isAccepted();
     }
@@ -107,6 +125,7 @@ void retryDeadLetteredReturnsNotFoundWhenNotFound() {
 
         webTestClient.post()
                 .uri("/api/v1/admin/convert/jobs/" + jobId + "/retry")
+                .header("X-Dummy", "dummy")
                 .exchange()
                 .expectStatus().isNotFound();
     }
@@ -118,6 +137,7 @@ void retryDeadLetteredReturnsConflictWhenNotEligible() {
 
         webTestClient.post()
                 .uri("/api/v1/admin/convert/jobs/" + jobId + "/retry")
+                .header("X-Dummy", "dummy")
                 .exchange()
                 .expectStatus().isEqualTo(409); // isConflict() isn't always available depending on spring-test version, so using isEqualTo(409) is safer
     }