diff --git a/.jules/sentinel.md b/.jules/sentinel.md
index e795cb9dd..9f18f4382 100644
--- a/.jules/sentinel.md
+++ b/.jules/sentinel.md
@@ -32,3 +32,8 @@
 **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.
+
+## 2026-10-15 - Missing Authorization on Admin Endpoints
+**Vulnerability:** The admin endpoints (`/api/v1/admin/convert/jobs/*`) lacked permission checks, allowing any tenant to view or manage conversion jobs belonging to other tenants.
+**Learning:** Endpoints intended for cross-tenant administration must strictly enforce dedicated administrative permissions (e.g., `admin:operate`). Missing these checks results in a critical authorization bypass.
+**Prevention:** Always secure administrative API endpoints with `TenantAccessService` and verify cross-tenant administrative privileges using specific, non-default permissions rather than relying solely on path obscurity.
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 1187deb2a..9733b2c15 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -24,6 +24,7 @@
 
 ### Security
 
+- 관리자용 엔드포인트(`GET /api/v1/admin/convert/jobs`, `DELETE /api/v1/admin/convert/jobs/{jobId}`, `POST /api/v1/admin/convert/jobs/{jobId}/retry`)에 교차 테넌트 접근 제어(`admin:operate` 권한 요구)를 추가하여 무단 접근 및 권한 상승 취약점을 해결했습니다.
 - `GET /api/v1/convert/jobs/{jobId}/download`가 리소스 조회 전에 전용 `artifact:read` 권한을 검증하고, PDF 저장소 접근 전에 작업의 tenant 소유권을 확인하도록 강화했습니다. `job:read`만으로는 문서 바이트를 읽을 수 없으며, 인증 누락·권한 누락·교차 tenant UUID 접근은 각각 fail closed 처리되고 교차 tenant 요청은 리소스 존재를 숨기는 `404`를 반환합니다.
 - Maven XML 테스트 보고서 검증기는 각 `testsuite`의 `tests`, `skipped`, `failures`, `errors` 속성을 모두 필수 증거로 요구합니다. 누락된 결과 수를 암묵적으로 0으로 간주하지 않고 fail closed 처리하며, 각 속성 누락 회귀 테스트를 추가했습니다.
 - Maven XML 테스트 보고서 검증기는 UTF-8만 허용하고 UTF-8 BOM은 수용하며, NUL 바이트·DTD·엔터티 선언을 파싱 전에 거부합니다. UTF-16 같은 대체 인코딩으로 위험 선언을 바이트 검사에서 숨기는 우회와 외부 엔터티 읽기·엔터티 확장형 서비스 거부를 회귀 테스트로 차단했습니다.
diff --git a/src/main/java/com/clearfolio/viewer/auth/TenantPermissions.java b/src/main/java/com/clearfolio/viewer/auth/TenantPermissions.java
index 4f9c6a685..a2273d9d2 100644
--- a/src/main/java/com/clearfolio/viewer/auth/TenantPermissions.java
+++ b/src/main/java/com/clearfolio/viewer/auth/TenantPermissions.java
@@ -55,6 +55,11 @@ public final class TenantPermissions {
      */
     public static final String ANALYTICS_READ = "analytics:read";
 
+    /**
+     * Permission required for cross-tenant administration.
+     */
+    public static final String ADMIN_OPERATE = "admin:operate";
+
     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 412d4eb86..8e74d46cc 100644
--- a/src/main/java/com/clearfolio/viewer/controller/AdminController.java
+++ b/src/main/java/com/clearfolio/viewer/controller/AdminController.java
@@ -12,8 +12,13 @@
 import org.springframework.web.bind.annotation.PostMapping;
 import org.springframework.web.bind.annotation.RequestParam;
 import org.springframework.web.bind.annotation.RestController;
+import org.springframework.web.bind.annotation.RequestHeader;
+import org.springframework.http.HttpHeaders;
 import org.springframework.web.server.ResponseStatusException;
 
+import com.clearfolio.viewer.auth.TenantAccessService;
+import com.clearfolio.viewer.auth.TenantPermissions;
+
 import com.clearfolio.viewer.api.AdminJobListResponse;
 import com.clearfolio.viewer.model.ConversionJob;
 import com.clearfolio.viewer.service.DocumentConversionService;
@@ -27,23 +32,33 @@ public class AdminController {
 
     private final DocumentConversionService conversionService;
 
+    private final TenantAccessService tenantAccessService;
+
     /**
      * Creates a controller for admin operations.
      *
      * @param conversionService conversion service
+     * @param tenantAccessService tenant and permission guard
      */
-    public AdminController(DocumentConversionService conversionService) {
+    public AdminController(
+            final DocumentConversionService conversionService,
+            final 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
      * @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_OPERATE);
         Iterable<ConversionJob> allJobs = conversionService.getAllJobs();
 
         if (deadLettered == null) {
@@ -63,10 +78,14 @@ 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_OPERATE);
         conversionService.deleteJob(jobId);
         return ResponseEntity.noContent().build();
     }
@@ -75,10 +94,14 @@ 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) {
+    public ResponseEntity<Void> retryDeadLettered(
+            @PathVariable final UUID jobId,
+            @RequestHeader final HttpHeaders headers) {
+        tenantAccessService.require(headers, TenantPermissions.ADMIN_OPERATE);
         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 ad63a8015..a82b153e2 100644
--- a/src/test/java/com/clearfolio/viewer/controller/AdminControllerTest.java
+++ b/src/test/java/com/clearfolio/viewer/controller/AdminControllerTest.java
@@ -10,6 +10,12 @@
 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 org.springframework.http.HttpHeaders;
+import java.util.Set;
+
 import com.clearfolio.viewer.model.ConversionJob;
 import com.clearfolio.viewer.service.DocumentConversionService;
 import com.clearfolio.viewer.service.RetryDeadLetterResult;
@@ -20,10 +26,16 @@ class AdminControllerTest {
     private WebTestClient webTestClient;
     private AdminController controller;
 
+    private static void addAuth(HttpHeaders headers, String permissions) {
+        headers.add(TenantContext.TENANT_ID_HEADER, "admin-tenant");
+        headers.add(TenantContext.SUBJECT_ID_HEADER, "admin-subject");
+        headers.add(TenantContext.PERMISSIONS_HEADER, permissions);
+    }
+
     @BeforeEach
     void setUp() {
         conversionService = mock(DocumentConversionService.class);
-        controller = new AdminController(conversionService);
+        controller = new AdminController(conversionService, new TenantAccessService());
         webTestClient = WebTestClient.bindToController(controller)
                 .controllerAdvice(new ApiExceptionHandler())
                 .build();
@@ -37,6 +49,7 @@ void getAllJobsReturnsAllJobsWhenNoFilterProvided() {
 
         webTestClient.get()
                 .uri("/api/v1/admin/convert/jobs")
+                .headers(headers -> addAuth(headers, TenantPermissions.ADMIN_OPERATE))
                 .exchange()
                 .expectStatus().isOk()
                 .expectBody()
@@ -55,6 +68,7 @@ void getAllJobsFiltersByDeadLetteredTrue() {
 
         webTestClient.get()
                 .uri("/api/v1/admin/convert/jobs?deadLettered=true")
+                .headers(headers -> addAuth(headers, TenantPermissions.ADMIN_OPERATE))
                 .exchange()
                 .expectStatus().isOk()
                 .expectBody()
@@ -72,6 +86,7 @@ void getAllJobsFiltersByDeadLetteredFalse() {
 
         webTestClient.get()
                 .uri("/api/v1/admin/convert/jobs?deadLettered=false")
+                .headers(headers -> addAuth(headers, TenantPermissions.ADMIN_OPERATE))
                 .exchange()
                 .expectStatus().isOk()
                 .expectBody()
@@ -85,6 +100,7 @@ void deleteJobReturnsNoContent() {
 
         webTestClient.delete()
                 .uri("/api/v1/admin/convert/jobs/" + jobId)
+                .headers(headers -> addAuth(headers, TenantPermissions.ADMIN_OPERATE))
                 .exchange()
                 .expectStatus().isNoContent();
     }
@@ -96,6 +112,7 @@ void retryDeadLetteredReturnsAcceptedWhenAccepted() {
 
         webTestClient.post()
                 .uri("/api/v1/admin/convert/jobs/" + jobId + "/retry")
+                .headers(headers -> addAuth(headers, TenantPermissions.ADMIN_OPERATE))
                 .exchange()
                 .expectStatus().isAccepted();
     }
@@ -107,6 +124,7 @@ void retryDeadLetteredReturnsNotFoundWhenNotFound() {
 
         webTestClient.post()
                 .uri("/api/v1/admin/convert/jobs/" + jobId + "/retry")
+                .headers(headers -> addAuth(headers, TenantPermissions.ADMIN_OPERATE))
                 .exchange()
                 .expectStatus().isNotFound();
     }
@@ -118,6 +136,7 @@ void retryDeadLetteredReturnsConflictWhenNotEligible() {
 
         webTestClient.post()
                 .uri("/api/v1/admin/convert/jobs/" + jobId + "/retry")
+                .headers(headers -> addAuth(headers, TenantPermissions.ADMIN_OPERATE))
                 .exchange()
                 .expectStatus().isEqualTo(409); // isConflict() isn't always available depending on spring-test version, so using isEqualTo(409) is safer
     }