diff --git a/backend/internal/handler/dev_handler.go b/backend/internal/handler/dev_handler.go
index 0b32a39a..e64e2e61 100644
--- a/backend/internal/handler/dev_handler.go
+++ b/backend/internal/handler/dev_handler.go
@@ -13,6 +13,7 @@ import (
 	"fmt"
 	"io"
 	"log/slog"
+	"net"
 	"net/http"
 	"net/url"
 	"os"
@@ -2749,16 +2750,35 @@ func validateBackchannelLogoutURI(raw string) error {
 	case "https":
 		return nil
 	case "http":
-		host := strings.ToLower(parsed.Hostname())
-		if host == "localhost" || host == "127.0.0.1" {
+		if isAllowedLocalBackchannelLogoutHost(parsed.Hostname()) {
 			return nil
 		}
-		return fmt.Errorf("backchannelLogoutUri must use https outside localhost development")
+		return fmt.Errorf("backchannelLogoutUri must use https outside local development")
 	default:
 		return fmt.Errorf("backchannelLogoutUri must use http or https")
 	}
 }
 
+func isAllowedLocalBackchannelLogoutHost(rawHost string) bool {
+	host := strings.ToLower(strings.TrimSpace(rawHost))
+	if host == "" {
+		return false
+	}
+
+	switch host {
+	case "localhost", "127.0.0.1", "::1", "host.docker.internal":
+		return true
+	}
+
+	if ip := net.ParseIP(host); ip != nil {
+		return ip.IsPrivate() || ip.IsLoopback() || ip.IsLinkLocalUnicast()
+	}
+
+	// Docker service names and other single-label local hostnames are
+	// permitted only for local HTTP development workflows.
+	return !strings.Contains(host, ".")
+}
+
 func normalizeClientAutoLoginMetadata(metadata map[string]interface{}) (map[string]interface{}, error) {
 	if metadata == nil {
 		return metadata, nil
diff --git a/devfront/src/features/clients/ClientGeneralPage.tsx b/devfront/src/features/clients/ClientGeneralPage.tsx
index b189abdd..8e3ace74 100644
--- a/devfront/src/features/clients/ClientGeneralPage.tsx
+++ b/devfront/src/features/clients/ClientGeneralPage.tsx
@@ -288,7 +288,26 @@ function isValidBackchannelLogoutUrl(value: string): boolean {
     if (url.protocol !== "http:") {
       return false;
     }
-    return url.hostname === "localhost" || url.hostname === "127.0.0.1";
+    const host = url.hostname.toLowerCase();
+    if (
+      host === "localhost" ||
+      host === "127.0.0.1" ||
+      host === "::1" ||
+      host === "host.docker.internal"
+    ) {
+      return true;
+    }
+    if (/^\d+\.\d+\.\d+\.\d+$/.test(host)) {
+      return (
+        host.startsWith("10.") ||
+        host.startsWith("192.168.") ||
+        /^172\.(1[6-9]|2\d|3[0-1])\./.test(host) ||
+        host.startsWith("169.254.")
+      );
+    }
+    // Docker service names and other single-label local hosts are allowed
+    // only for HTTP local development use.
+    return !host.includes(".");
   } catch {
     return false;
   }
@@ -949,7 +968,7 @@ function ClientGeneralPage() {
         throw new Error(
           t(
             "msg.dev.clients.general.backchannel_logout.invalid",
-            "Back-Channel Logout URI 형식이 올바르지 않습니다. 운영 환경은 https, 로컬 개발 환경은 localhost/127.0.0.1의 http만 허용됩니다.",
+            "Back-Channel Logout URI 형식이 올바르지 않습니다. 운영 환경은 https를 사용하고, 로컬 개발 환경은 localhost/127.0.0.1, host.docker.internal, Docker 서비스명, 사설 IP의 http만 허용됩니다.",
           ),
         );
       }
@@ -1590,7 +1609,7 @@ function ClientGeneralPage() {
                 <p className="text-xs text-destructive">
                   {t(
                     "msg.dev.clients.general.backchannel_logout.invalid",
-                    "Back-Channel Logout URI 형식이 올바르지 않습니다. 운영 환경은 https, 로컬 개발 환경은 localhost/127.0.0.1의 http만 허용됩니다.",
+                    "Back-Channel Logout URI 형식이 올바르지 않습니다. 운영 환경은 https를 사용하고, 로컬 개발 환경은 localhost/127.0.0.1, host.docker.internal, Docker 서비스명, 사설 IP의 http만 허용됩니다.",
                   )}
                 </p>
               ) : null}
diff --git a/devfront/src/locales/en.toml b/devfront/src/locales/en.toml
index a4d69010..f7daf9d7 100644
--- a/devfront/src/locales/en.toml
+++ b/devfront/src/locales/en.toml
@@ -435,7 +435,7 @@ help = "Enter the redirect URIs. You can modify them in the Federation tab after
 
 [msg.dev.clients.general.backchannel_logout]
 uri_help = "RP endpoint that receives Baron's session termination event via server-to-server POST."
-invalid = "The Back-Channel Logout URI format is invalid. Production requires https, and local development only allows http on localhost/127.0.0.1."
+invalid = "The Back-Channel Logout URI format is invalid. Production requires https, and local development only allows http on localhost/127.0.0.1, host.docker.internal, Docker service names, and private IPs."
 session_required_help = "Use this when the RP should process logout_token only if the sid claim is included."
 session_required_on = "On: process logout only when the logout_token contains a sid."
 session_required_off = "Off: process logout using sub even if sid is missing."
diff --git a/devfront/src/locales/ko.toml b/devfront/src/locales/ko.toml
index eecb25aa..678f9a7d 100644
--- a/devfront/src/locales/ko.toml
+++ b/devfront/src/locales/ko.toml
@@ -435,7 +435,7 @@ help = "인증 후 리다이렉트될 URI를 입력하세요. 생성 후 연동
 
 [msg.dev.clients.general.backchannel_logout]
 uri_help = "Baron이 세션 종료 이벤트를 서버 간 POST로 전달할 RP endpoint입니다."
-invalid = "Back-Channel Logout URI 형식이 올바르지 않습니다. 운영 환경은 https, 로컬 개발 환경은 localhost/127.0.0.1의 http만 허용됩니다."
+invalid = "Back-Channel Logout URI 형식이 올바르지 않습니다. 운영 환경은 https를 사용하고, 로컬 개발 환경은 localhost/127.0.0.1, host.docker.internal, Docker 서비스명, 사설 IP의 http만 허용됩니다."
 session_required_help = "RP가 logout_token에 sid claim이 포함된 경우에만 처리하도록 요구할 때 사용합니다."
 session_required_on = "켜면: logout_token 안에 sid가 있을 때만 로그아웃 처리"
 session_required_off = "끄면: sid가 없어도 sub만으로 로그아웃 처리 가능"