diff --git a/.jules/sentinel.md b/.jules/sentinel.md
index e795cb9dd..755e4b27f 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.
+
+## 2026-08-19 - 런타임 시크릿 설정 방식 변경
+**Vulnerability:** 환경 변수를 통해 런타임 시크릿(artifact token secret 및 tenant claims HMAC secret)을 직접 주입하고 있었으며, 이는 컨테이너나 프로세스 환경에 민감한 정보가 노출될 위험이 존재했습니다.
+**Learning:** `AGENTS.md`의 보안 지침에 따라 환경 변수는 런타임 애플리케이션의 설정 값이 아닌 KV 저장소(configtree 등)를 부트스트랩하기 위한 경로로만 사용되어야 합니다. 또한 Spring Boot 설정에서 `@Value` 어노테이션의 기본값을 완전히 제거하여 설정 트리의 값이 없을 경우 빈 문자열로 덮어씌워지지 않도록 해야 합니다.
+**Prevention:** 향후 런타임 시크릿 및 권한 증명과 관련된 새로운 변수가 추가될 때, 환경 변수 주입 방식이 아닌 반드시 KV 기반의 조회 방식(configtree 마운트 등)과 `@Value("${property.name}")` 형식의 기본값 없는 엄격한 주입을 사용해야 합니다.
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 1187deb2a..87881b490 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -70,3 +70,6 @@
 - 루트 `LICENSE`와 Maven license metadata를 추가해 Scorecard License alert가 표준 Apache-2.0 파일을 확인할 수 있게 했습니다.
 - logback-core 신규 권고(GHSA-jhq6-gfmj-v8fx) 대응을 위해 Logback 관리 버전을 `1.5.35`로 고정했습니다.
 - 저장소 보안 정책, Maven/GitHub Actions Dependabot 설정, 기본 CodeQL/중앙 SAST 운영 지침, 다운로드 파일명 정규화 Jazzer fuzz target을 추가해 Scorecard 보안 거버넌스 신호를 보강했습니다.
+
+### 보안 (Security)
+- 런타임 환경 변수 대신 Spring Boot configtree를 통해 인증 시크릿(artifact token secret 및 tenant claims HMAC secret)을 로드하도록 마이그레이션했습니다.
diff --git a/src/main/java/com/clearfolio/viewer/artifact/ArtifactLinkService.java b/src/main/java/com/clearfolio/viewer/artifact/ArtifactLinkService.java
index 79a972e3d..bcee94fda 100644
--- a/src/main/java/com/clearfolio/viewer/artifact/ArtifactLinkService.java
+++ b/src/main/java/com/clearfolio/viewer/artifact/ArtifactLinkService.java
@@ -79,7 +79,7 @@ public class ArtifactLinkService {
     public ArtifactLinkService(
             ArtifactStore artifactStore,
             ArtifactLinkLedger artifactLinkLedger,
-            @Value("${clearfolio.artifact-token.secret:}") String configuredSecret) {
+            @Value("${clearfolio.artifact-token.secret}") String configuredSecret) {
         this(artifactStore, artifactLinkLedger, configuredSecret, Clock.systemUTC(), new SecureRandom());
     }
 
diff --git a/src/main/java/com/clearfolio/viewer/auth/TenantAccessService.java b/src/main/java/com/clearfolio/viewer/auth/TenantAccessService.java
index ab02e96a7..4531e0469 100644
--- a/src/main/java/com/clearfolio/viewer/auth/TenantAccessService.java
+++ b/src/main/java/com/clearfolio/viewer/auth/TenantAccessService.java
@@ -47,7 +47,7 @@ public TenantAccessService() {
      */
     @Autowired
     public TenantAccessService(
-            @Value("${clearfolio.tenant-claims.hmac-secret:}") String claimsHmacSecret,
+            @Value("${clearfolio.tenant-claims.hmac-secret}") String claimsHmacSecret,
             @Value("${clearfolio.tenant-claims.max-skew-seconds:300}") long maxSkewSeconds) {
         this(claimsHmacSecret, maxSkewSeconds, Clock.systemUTC());
     }
diff --git a/src/main/java/com/clearfolio/viewer/config/ProductionAuthReadinessConfig.java b/src/main/java/com/clearfolio/viewer/config/ProductionAuthReadinessConfig.java
index dfeb00a59..9752c40dd 100644
--- a/src/main/java/com/clearfolio/viewer/config/ProductionAuthReadinessConfig.java
+++ b/src/main/java/com/clearfolio/viewer/config/ProductionAuthReadinessConfig.java
@@ -18,7 +18,7 @@ public class ProductionAuthReadinessConfig {
      * @param tenantClaimsSecret shared gateway signing secret
      */
     public ProductionAuthReadinessConfig(
-            @Value("${clearfolio.tenant-claims.hmac-secret:}") String tenantClaimsSecret) {
+            @Value("${clearfolio.tenant-claims.hmac-secret}") String tenantClaimsSecret) {
         if (!StringUtils.hasText(tenantClaimsSecret)) {
             throw new IllegalStateException(
                     "production profile requires clearfolio.tenant-claims.hmac-secret"
diff --git a/src/main/resources/application-buyer-demo.yml b/src/main/resources/application-buyer-demo.yml
index 4e4df4091..56e5437ac 100644
--- a/src/main/resources/application-buyer-demo.yml
+++ b/src/main/resources/application-buyer-demo.yml
@@ -23,9 +23,7 @@ viewer:
 
 clearfolio:
   artifact-token:
-    secret: ${CLEARFOLIO_ARTIFACT_TOKEN_SECRET:}
   tenant-claims:
-    hmac-secret: ${CLEARFOLIO_TENANT_CLAIMS_HMAC_SECRET:}
     max-skew-seconds: ${CLEARFOLIO_TENANT_CLAIMS_MAX_SKEW_SECONDS:300}
   artifact-link-ledger:
     path: ${CLEARFOLIO_ARTIFACT_LINK_LEDGER_PATH:}
diff --git a/src/test/java/com/clearfolio/viewer/config/ProductionAuthReadinessConfigTest.java b/src/test/java/com/clearfolio/viewer/config/ProductionAuthReadinessConfigTest.java
index f00ba4c62..a15252cb0 100644
--- a/src/test/java/com/clearfolio/viewer/config/ProductionAuthReadinessConfigTest.java
+++ b/src/test/java/com/clearfolio/viewer/config/ProductionAuthReadinessConfigTest.java
@@ -3,14 +3,19 @@
 import static org.assertj.core.api.Assertions.assertThat;
 
 import org.junit.jupiter.api.Test;
+import org.springframework.beans.factory.BeanCreationException;
 import org.springframework.boot.test.context.runner.ApplicationContextRunner;
 
 class ProductionAuthReadinessConfigTest {
 
     @Test
     void productionProfileFailsWithoutSignedTenantClaimsSecret() {
-        productionRunner().run(context -> assertThat(context.getStartupFailure())
-                .hasRootCauseMessage("production profile requires clearfolio.tenant-claims.hmac-secret"));
+        productionRunner()
+                .withPropertyValues("clearfolio.tenant-claims.hmac-secret=")
+                .run(context -> {
+                    assertThat(context.getStartupFailure()).isNotNull();
+                    assertThat(context.getStartupFailure()).hasRootCauseMessage("production profile requires clearfolio.tenant-claims.hmac-secret");
+                });
     }
 
     @Test