diff --git a/extensions/line/src/monitor.lifecycle.test.ts b/extensions/line/src/monitor.lifecycle.test.ts
index f4561ead08a3..f13e6ee54fea 100644
--- a/extensions/line/src/monitor.lifecycle.test.ts
+++ b/extensions/line/src/monitor.lifecycle.test.ts
@@ -1,7 +1,7 @@
 // Line tests cover monitor.lifecycle plugin behavior.
 import crypto from "node:crypto";
 import { EventEmitter } from "node:events";
-import type { IncomingMessage, ServerResponse } from "node:http";
+import { createServer, type IncomingMessage, type ServerResponse } from "node:http";
 import type { OpenClawConfig } from "openclaw/plugin-sdk/config-contracts";
 import type { RuntimeEnv } from "openclaw/plugin-sdk/runtime-env";
 import { createMockIncomingRequest } from "openclaw/plugin-sdk/test-env";
@@ -378,6 +378,102 @@ describe("monitorLineProvider lifecycle", () => {
     await secondMonitor.stop();
   });
 
+  it("redacts structured admission failures from signed HTTP webhook requests", async () => {
+    const runtimeError = vi.fn<(...args: unknown[]) => void>();
+    const runtime: RuntimeEnv = {
+      log: vi.fn<(...args: unknown[]) => void>(),
+      error: runtimeError,
+      exit: vi.fn<(code: number) => void>(),
+    };
+    const monitor = await monitorLineProvider({
+      channelAccessToken: "token",
+      channelSecret: "secret", // pragma: allowlist secret
+      accountId: "default",
+      config: {} as OpenClawConfig,
+      runtime,
+    });
+    const route = requireRegisteredRoute();
+    const server = createServer((req, res) => {
+      void route.handler(req, res);
+    });
+
+    try {
+      await new Promise<void>((resolve, reject) => {
+        server.once("error", reject);
+        server.listen(0, "127.0.0.1", () => {
+          server.removeListener("error", reject);
+          resolve();
+        });
+      });
+      const address = server.address();
+      if (!address || typeof address === "string") {
+        throw new Error("expected LINE webhook test server to have a TCP address");
+      }
+
+      const webhookUrl = `http://127.0.0.1:${address.port}/line/webhook`;
+      const payload = JSON.stringify({ events: [{ type: "message" }] });
+      const rejected = await fetch(webhookUrl, {
+        method: "POST",
+        headers: {
+          "content-type": "application/json",
+          "x-line-signature": "invalid-signature",
+        },
+        body: payload,
+      });
+      expect(rejected.status).toBe(401);
+      expect(await rejected.json()).toEqual({ error: "Invalid signature" });
+
+      const bot = createLineBotMock.mock.results[0]?.value;
+      if (!bot) {
+        throw new Error("expected registered LINE webhook bot");
+      }
+      expect(bot.handleWebhook).not.toHaveBeenCalled();
+
+      const bearerToken = "test_line_access_token_1234567890";
+      bot.handleWebhook.mockRejectedValueOnce({
+        code: "LINE_ADMISSION_REJECTED",
+        retryAfterMs: 250,
+        authorization: `Bearer ${bearerToken}`,
+      });
+      const signature = crypto.createHmac("SHA256", "secret").update(payload).digest("base64");
+      const response = await fetch(webhookUrl, {
+        method: "POST",
+        headers: {
+          "content-type": "application/json",
+          "x-line-signature": signature,
+        },
+        body: payload,
+      });
+
+      expect(response.status).toBe(500);
+      expect(await response.json()).toEqual({ error: "Internal server error" });
+      expect(bot.handleWebhook).toHaveBeenCalledTimes(1);
+      expect(runtimeError).toHaveBeenCalledTimes(1);
+      const message = String(runtimeError.mock.calls[0]?.[0]);
+      expect(message).toContain("line webhook error:");
+      expect(message).toContain("LINE_ADMISSION_REJECTED");
+      expect(message).toContain("retryAfterMs");
+      expect(message).not.toContain("[object Object]");
+      expect(message).not.toContain(bearerToken);
+    } finally {
+      try {
+        if (server.listening) {
+          await new Promise<void>((resolve, reject) => {
+            server.close((error) => {
+              if (error) {
+                reject(error);
+                return;
+              }
+              resolve();
+            });
+          });
+        }
+      } finally {
+        await monitor.stop();
+      }
+    }
+  });
+
   it("dispatches a signed POST to a configured trailing-slash webhook path", async () => {
     const monitor = await monitorLineProvider({
       channelAccessToken: "token",
diff --git a/extensions/line/src/monitor.ts b/extensions/line/src/monitor.ts
index 693a7a0b7fe1..5077ca2cde2c 100644
--- a/extensions/line/src/monitor.ts
+++ b/extensions/line/src/monitor.ts
@@ -2,6 +2,7 @@
 import type { webhook } from "@line/bot-sdk";
 import { hasFinalInboundReplyDispatch } from "openclaw/plugin-sdk/channel-inbound";
 import type { OpenClawConfig } from "openclaw/plugin-sdk/config-contracts";
+import { formatErrorMessage } from "openclaw/plugin-sdk/error-runtime";
 import { chunkMarkdownText } from "openclaw/plugin-sdk/reply-runtime";
 import {
   danger,
@@ -392,7 +393,7 @@ export async function monitorLineProvider(
             res.end(JSON.stringify({ error: requestBodyErrorToText("REQUEST_BODY_TIMEOUT") }));
             return;
           }
-          runtime.error?.(danger(`line webhook error: ${String(err)}`));
+          runtime.error?.(danger(`line webhook error: ${formatErrorMessage(err)}`));
           if (!res.headersSent) {
             res.statusCode = 500;
             res.setHeader("Content-Type", "application/json");
diff --git a/extensions/line/src/webhook-node.test.ts b/extensions/line/src/webhook-node.test.ts
index 24832007ed71..42d1e3ac345f 100644
--- a/extensions/line/src/webhook-node.test.ts
+++ b/extensions/line/src/webhook-node.test.ts
@@ -183,18 +183,19 @@ type WebhookPostResult = {
 };
 
 type WebhookPostInvoker = (params: {
-  failWith?: Error;
+  failWith?: unknown;
   rawBody: string;
   signed: boolean;
 }) => Promise<WebhookPostResult>;
 
 async function invokeNodePostContract(params: {
-  failWith?: Error;
+  failWith?: unknown;
   rawBody: string;
   signed: boolean;
 }) {
   const dispatched = vi.fn(async () => {
     if (params.failWith) {
+      // oxlint-disable-next-line typescript/only-throw-error -- Webhook boundaries must report non-Error throws from downstream dispatchers.
       throw params.failWith;
     }
   });
@@ -223,13 +224,14 @@ async function invokeNodePostContract(params: {
 }
 
 async function invokeMiddlewarePostContract(params: {
-  failWith?: Error;
+  failWith?: unknown;
   rawBody: string;
   signed: boolean;
 }) {
   const runtime = createRuntimeMock();
   const onEvents = vi.fn(async () => {
     if (params.failWith) {
+      // oxlint-disable-next-line typescript/only-throw-error -- Webhook boundaries must report non-Error throws from downstream dispatchers.
       throw params.failWith;
     }
   });
@@ -354,6 +356,26 @@ describe("LINE webhook shared POST contract", () => {
       expect(result.runtimeError).toHaveBeenCalledTimes(1);
     },
   );
+
+  it.each(sharedWebhookPostContractCases)(
+    "$name reports non-Error admission failures without object Object",
+    async ({ invoke }) => {
+      const result = await invoke({
+        failWith: { code: "LINE_ADMISSION_REJECTED", retryAfterMs: 250 },
+        rawBody: JSON.stringify({ events: [{ type: "message" }] }),
+        signed: true,
+      });
+
+      expect(result.status).toBe(500);
+      expect(result.body).toEqual({ error: "Internal server error" });
+      expect(result.runtimeError).toHaveBeenCalledTimes(1);
+      const runtimeMessage = String(firstMockCall(result.runtimeError, "runtime error")[0]);
+      expect(runtimeMessage).toContain("line webhook error:");
+      expect(runtimeMessage).toContain("LINE_ADMISSION_REJECTED");
+      expect(runtimeMessage).toContain("retryAfterMs");
+      expect(runtimeMessage).not.toContain("[object Object]");
+    },
+  );
 });
 
 describe("createLineNodeWebhookHandler", () => {
diff --git a/extensions/line/src/webhook-node.ts b/extensions/line/src/webhook-node.ts
index 35881291371d..936e8428404d 100644
--- a/extensions/line/src/webhook-node.ts
+++ b/extensions/line/src/webhook-node.ts
@@ -1,6 +1,7 @@
 // Line plugin module implements webhook node behavior.
 import type { IncomingMessage, ServerResponse } from "node:http";
 import type { webhook } from "@line/bot-sdk";
+import { formatErrorMessage } from "openclaw/plugin-sdk/error-runtime";
 import { danger, logVerbose, type RuntimeEnv } from "openclaw/plugin-sdk/runtime-env";
 import {
   isRequestBodyLimitError,
@@ -119,7 +120,7 @@ export function createLineNodeWebhookHandler(params: {
         res.end(JSON.stringify({ error: requestBodyErrorToText("REQUEST_BODY_TIMEOUT") }));
         return;
       }
-      params.runtime.error?.(danger(`line webhook error: ${String(err)}`));
+      params.runtime.error?.(danger(`line webhook error: ${formatErrorMessage(err)}`));
       if (!res.headersSent) {
         res.statusCode = 500;
         res.setHeader("Content-Type", "application/json");
diff --git a/extensions/line/src/webhook.ts b/extensions/line/src/webhook.ts
index cc78348d1365..55ec00c4ebc8 100644
--- a/extensions/line/src/webhook.ts
+++ b/extensions/line/src/webhook.ts
@@ -1,6 +1,7 @@
 // Line plugin module implements webhook behavior.
 import type { webhook } from "@line/bot-sdk";
 import type { NextFunction, Request, Response } from "express";
+import { formatErrorMessage } from "openclaw/plugin-sdk/error-runtime";
 import { danger, logVerbose, type RuntimeEnv } from "openclaw/plugin-sdk/runtime-env";
 import { parseLineWebhookBody, validateLineSignature } from "./webhook-utils.js";
 
@@ -73,7 +74,7 @@ export function createLineWebhookMiddleware(
       }
       res.status(200).json({ status: "ok" });
     } catch (err) {
-      runtime?.error?.(danger(`line webhook error: ${String(err)}`));
+      runtime?.error?.(danger(`line webhook error: ${formatErrorMessage(err)}`));
       if (!res.headersSent) {
         res.status(500).json({ error: "Internal server error" });
       }