diff --git a/CHANGELOG.md b/CHANGELOG.md
index 65c6d2990..64e8ad6bb 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -12,6 +12,7 @@ Docs: https://docs.openclaw.ai
 
 ### Fixes
 
+- Gateway/WS: close repeated post-handshake `unauthorized role:*` request floods per connection and sample duplicate rejection logs, preventing a single misbehaving client from degrading gateway responsiveness. (#20168) Thanks @acy103, @vibecodooor, and @vincentkoc.
 - Agents/Reasoning: when model-default thinking is active (for example `thinking=low`), keep auto-reasoning disabled unless explicitly enabled, preventing `Reasoning:` thinking-block leakage in channel replies. (#24335, #24290) thanks @Kay-051.
 - Auto-reply/Inbound metadata: hide direct-chat `message_id`/`message_id_full` and sender metadata only from normalized chat type (not sender-id sentinels), preserving group metadata visibility and preventing sender-id spoofed direct-mode classification. (#24373) thanks @jd316.
 - Security/Exec: detect obfuscated commands before exec allowlist decisions and require explicit approval for obfuscation patterns. (#8592) Thanks @CornBrother0x and @vincentkoc.
diff --git a/src/gateway/server/ws-connection/message-handler.ts b/src/gateway/server/ws-connection/message-handler.ts
index e8f8659a9..eb62269c8 100644
--- a/src/gateway/server/ws-connection/message-handler.ts
+++ b/src/gateway/server/ws-connection/message-handler.ts
@@ -78,6 +78,7 @@ import {
   resolveControlUiAuthPolicy,
   shouldSkipControlUiPairing,
 } from "./connect-policy.js";
+import { isUnauthorizedRoleError, UnauthorizedFloodGuard } from "./unauthorized-flood-guard.js";
 
 type SubsystemLogger = ReturnType<typeof createSubsystemLogger>;
 
@@ -190,6 +191,7 @@ export function attachGatewayWsMessageHandler(params: {
   }
 
   const isWebchatConnect = (p: ConnectParams | null | undefined) => isWebchatClient(p?.client);
+  const unauthorizedFloodGuard = new UnauthorizedFloodGuard();
 
   socket.on("message", async (data) => {
     if (isClosed()) {
@@ -908,6 +910,33 @@ export function attachGatewayWsMessageHandler(params: {
         meta?: Record<string, unknown>,
       ) => {
         send({ type: "res", id: req.id, ok, payload, error });
+        const unauthorizedRoleError = isUnauthorizedRoleError(error);
+        let logMeta = meta;
+        if (unauthorizedRoleError) {
+          const unauthorizedDecision = unauthorizedFloodGuard.registerUnauthorized();
+          if (unauthorizedDecision.suppressedSinceLastLog > 0) {
+            logMeta = {
+              ...logMeta,
+              suppressedUnauthorizedResponses: unauthorizedDecision.suppressedSinceLastLog,
+            };
+          }
+          if (!unauthorizedDecision.shouldLog) {
+            return;
+          }
+          if (unauthorizedDecision.shouldClose) {
+            setCloseCause("repeated-unauthorized-requests", {
+              unauthorizedCount: unauthorizedDecision.count,
+              method: req.method,
+            });
+            queueMicrotask(() => close(1008, "repeated unauthorized calls"));
+          }
+          logMeta = {
+            ...logMeta,
+            unauthorizedCount: unauthorizedDecision.count,
+          };
+        } else {
+          unauthorizedFloodGuard.reset();
+        }
         logWs("out", "res", {
           connId,
           id: req.id,
@@ -915,7 +944,7 @@ export function attachGatewayWsMessageHandler(params: {
           method: req.method,
           errorCode: error?.code,
           errorMessage: error?.message,
-          ...meta,
+          ...logMeta,
         });
       };
 
diff --git a/src/gateway/server/ws-connection/unauthorized-flood-guard.test.ts b/src/gateway/server/ws-connection/unauthorized-flood-guard.test.ts
new file mode 100644
index 000000000..8c750570d
--- /dev/null
+++ b/src/gateway/server/ws-connection/unauthorized-flood-guard.test.ts
@@ -0,0 +1,67 @@
+import { describe, expect, it } from "vitest";
+import { ErrorCodes, errorShape } from "../../protocol/index.js";
+import { isUnauthorizedRoleError, UnauthorizedFloodGuard } from "./unauthorized-flood-guard.js";
+
+describe("UnauthorizedFloodGuard", () => {
+  it("suppresses repeated unauthorized responses and closes after threshold", () => {
+    const guard = new UnauthorizedFloodGuard({ closeAfter: 2, logEvery: 3 });
+
+    const first = guard.registerUnauthorized();
+    expect(first).toEqual({
+      shouldClose: false,
+      shouldLog: true,
+      count: 1,
+      suppressedSinceLastLog: 0,
+    });
+
+    const second = guard.registerUnauthorized();
+    expect(second).toEqual({
+      shouldClose: false,
+      shouldLog: false,
+      count: 2,
+      suppressedSinceLastLog: 0,
+    });
+
+    const third = guard.registerUnauthorized();
+    expect(third).toEqual({
+      shouldClose: true,
+      shouldLog: true,
+      count: 3,
+      suppressedSinceLastLog: 1,
+    });
+  });
+
+  it("resets counters", () => {
+    const guard = new UnauthorizedFloodGuard({ closeAfter: 10, logEvery: 50 });
+    guard.registerUnauthorized();
+    guard.registerUnauthorized();
+    guard.reset();
+
+    const next = guard.registerUnauthorized();
+    expect(next).toEqual({
+      shouldClose: false,
+      shouldLog: true,
+      count: 1,
+      suppressedSinceLastLog: 0,
+    });
+  });
+});
+
+describe("isUnauthorizedRoleError", () => {
+  it("detects unauthorized role responses", () => {
+    expect(
+      isUnauthorizedRoleError(errorShape(ErrorCodes.INVALID_REQUEST, "unauthorized role: node")),
+    ).toBe(true);
+  });
+
+  it("ignores non-role authorization errors", () => {
+    expect(
+      isUnauthorizedRoleError(
+        errorShape(ErrorCodes.INVALID_REQUEST, "missing scope: operator.admin"),
+      ),
+    ).toBe(false);
+    expect(isUnauthorizedRoleError(errorShape(ErrorCodes.UNAVAILABLE, "service unavailable"))).toBe(
+      false,
+    );
+  });
+});
diff --git a/src/gateway/server/ws-connection/unauthorized-flood-guard.ts b/src/gateway/server/ws-connection/unauthorized-flood-guard.ts
new file mode 100644
index 000000000..f7a7636b5
--- /dev/null
+++ b/src/gateway/server/ws-connection/unauthorized-flood-guard.ts
@@ -0,0 +1,69 @@
+import { ErrorCodes, type ErrorShape } from "../../protocol/index.js";
+
+export type UnauthorizedFloodGuardOptions = {
+  closeAfter?: number;
+  logEvery?: number;
+};
+
+export type UnauthorizedFloodDecision = {
+  shouldClose: boolean;
+  shouldLog: boolean;
+  count: number;
+  suppressedSinceLastLog: number;
+};
+
+const DEFAULT_CLOSE_AFTER = 10;
+const DEFAULT_LOG_EVERY = 100;
+
+export class UnauthorizedFloodGuard {
+  private readonly closeAfter: number;
+  private readonly logEvery: number;
+  private count = 0;
+  private suppressedSinceLastLog = 0;
+
+  constructor(options?: UnauthorizedFloodGuardOptions) {
+    this.closeAfter = Math.max(1, Math.floor(options?.closeAfter ?? DEFAULT_CLOSE_AFTER));
+    this.logEvery = Math.max(1, Math.floor(options?.logEvery ?? DEFAULT_LOG_EVERY));
+  }
+
+  registerUnauthorized(): UnauthorizedFloodDecision {
+    this.count += 1;
+    const shouldClose = this.count > this.closeAfter;
+    const shouldLog = this.count === 1 || this.count % this.logEvery === 0 || shouldClose;
+
+    if (!shouldLog) {
+      this.suppressedSinceLastLog += 1;
+      return {
+        shouldClose,
+        shouldLog: false,
+        count: this.count,
+        suppressedSinceLastLog: 0,
+      };
+    }
+
+    const suppressedSinceLastLog = this.suppressedSinceLastLog;
+    this.suppressedSinceLastLog = 0;
+    return {
+      shouldClose,
+      shouldLog: true,
+      count: this.count,
+      suppressedSinceLastLog,
+    };
+  }
+
+  reset(): void {
+    this.count = 0;
+    this.suppressedSinceLastLog = 0;
+  }
+}
+
+export function isUnauthorizedRoleError(error?: ErrorShape): boolean {
+  if (!error) {
+    return false;
+  }
+  return (
+    error.code === ErrorCodes.INVALID_REQUEST &&
+    typeof error.message === "string" &&
+    error.message.startsWith("unauthorized role:")
+  );
+}