diff --git a/CHANGELOG.md b/CHANGELOG.md
index 33d01f95cc8..936ff55f561 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -28,6 +28,7 @@ Docs: https://docs.openclaw.ai
 
 ### Fixes
 
+- Security/Feishu: enforce ID-only allowlist matching for DM/group sender authorization, normalize Feishu ID prefixes during checks, and ignore mutable display names so display-name collisions cannot satisfy allowlist entries. This ships in the next npm release. Thanks @jiseoung for reporting.
 - Hooks/Cron: suppress duplicate main-session events for delivered hook turns and mark `SILENT_REPLY_TOKEN` (`NO_REPLY`) early exits as delivered to prevent hook context pollution. (#20678) Thanks @JonathanWorks.
 - Providers/OpenRouter: inject `cache_control` on system prompts for OpenRouter Anthropic models to improve prompt-cache reuse. (#17473) Thanks @rrenamed.
 - Installer/Smoke tests: remove legacy `OPENCLAW_USE_GUM` overrides from docker install-smoke runs so tests exercise installer auto TTY detection behavior directly.
diff --git a/extensions/feishu/src/bot.ts b/extensions/feishu/src/bot.ts
index 2cf30c44067..ba48abb60cb 100644
--- a/extensions/feishu/src/bot.ts
+++ b/extensions/feishu/src/bot.ts
@@ -522,6 +522,7 @@ export async function handleFeishuMessage(params: {
 
   let ctx = parseFeishuMessageEvent(event, botOpenId);
   const isGroup = ctx.chatType === "group";
+  const senderUserId = event.sender.sender_id.user_id?.trim() || undefined;
 
   // Resolve sender display name (best-effort) so the agent can attribute messages correctly.
   const senderResult = await resolveFeishuSenderName({
@@ -601,6 +602,7 @@ export async function handleFeishuMessage(params: {
         groupPolicy: "allowlist",
         allowFrom: senderAllowFrom,
         senderId: ctx.senderOpenId,
+        senderIds: [senderUserId],
         senderName: ctx.senderName,
       });
       if (!senderAllowed) {
@@ -653,6 +655,7 @@ export async function handleFeishuMessage(params: {
     const dmAllowed = resolveFeishuAllowlistMatch({
       allowFrom: effectiveDmAllowFrom,
       senderId: ctx.senderOpenId,
+      senderIds: [senderUserId],
       senderName: ctx.senderName,
     }).allowed;
 
@@ -694,6 +697,7 @@ export async function handleFeishuMessage(params: {
     const senderAllowedForCommands = resolveFeishuAllowlistMatch({
       allowFrom: commandAllowFrom,
       senderId: ctx.senderOpenId,
+      senderIds: [senderUserId],
       senderName: ctx.senderName,
     }).allowed;
     const commandAuthorized = shouldComputeCommandAuthorized
diff --git a/extensions/feishu/src/policy.test.ts b/extensions/feishu/src/policy.test.ts
new file mode 100644
index 00000000000..8e7d24ba67b
--- /dev/null
+++ b/extensions/feishu/src/policy.test.ts
@@ -0,0 +1,59 @@
+import { describe, expect, it } from "vitest";
+import { isFeishuGroupAllowed, resolveFeishuAllowlistMatch } from "./policy.js";
+
+describe("feishu policy", () => {
+  describe("resolveFeishuAllowlistMatch", () => {
+    it("allows wildcard", () => {
+      expect(
+        resolveFeishuAllowlistMatch({
+          allowFrom: ["*"],
+          senderId: "ou-attacker",
+        }),
+      ).toEqual({ allowed: true, matchKey: "*", matchSource: "wildcard" });
+    });
+
+    it("matches normalized ID entries", () => {
+      expect(
+        resolveFeishuAllowlistMatch({
+          allowFrom: ["feishu:user:OU_ALLOWED"],
+          senderId: "ou_allowed",
+        }),
+      ).toEqual({ allowed: true, matchKey: "ou_allowed", matchSource: "id" });
+    });
+
+    it("supports user_id as an additional immutable sender candidate", () => {
+      expect(
+        resolveFeishuAllowlistMatch({
+          allowFrom: ["on_user_123"],
+          senderId: "ou_other",
+          senderIds: ["on_user_123"],
+        }),
+      ).toEqual({ allowed: true, matchKey: "on_user_123", matchSource: "id" });
+    });
+
+    it("does not authorize based on display-name collision", () => {
+      const victimOpenId = "ou_4f4ec5aa111122223333444455556666";
+
+      expect(
+        resolveFeishuAllowlistMatch({
+          allowFrom: [victimOpenId],
+          senderId: "ou_attacker_real_open_id",
+          senderIds: ["on_attacker_user_id"],
+          senderName: victimOpenId,
+        }),
+      ).toEqual({ allowed: false });
+    });
+  });
+
+  describe("isFeishuGroupAllowed", () => {
+    it("matches group IDs with chat: prefix", () => {
+      expect(
+        isFeishuGroupAllowed({
+          groupPolicy: "allowlist",
+          allowFrom: ["chat:oc_group_123"],
+          senderId: "oc_group_123",
+        }),
+      ).toBe(true);
+    });
+  });
+});
diff --git a/extensions/feishu/src/policy.ts b/extensions/feishu/src/policy.ts
index 89e12ba859e..6ddac42d0e6 100644
--- a/extensions/feishu/src/policy.ts
+++ b/extensions/feishu/src/policy.ts
@@ -3,17 +3,52 @@ import type {
   ChannelGroupContext,
   GroupToolPolicyConfig,
 } from "openclaw/plugin-sdk";
-import { resolveAllowlistMatchSimple } from "openclaw/plugin-sdk";
+import { normalizeFeishuTarget } from "./targets.js";
 import type { FeishuConfig, FeishuGroupConfig } from "./types.js";
 
-export type FeishuAllowlistMatch = AllowlistMatch<"wildcard" | "id" | "name">;
+export type FeishuAllowlistMatch = AllowlistMatch<"wildcard" | "id">;
+
+function normalizeFeishuAllowEntry(raw: string): string {
+  const trimmed = raw.trim();
+  if (!trimmed) {
+    return "";
+  }
+  if (trimmed === "*") {
+    return "*";
+  }
+  const withoutProviderPrefix = trimmed.replace(/^feishu:/i, "");
+  const normalized = normalizeFeishuTarget(withoutProviderPrefix) ?? withoutProviderPrefix;
+  return normalized.trim().toLowerCase();
+}
 
 export function resolveFeishuAllowlistMatch(params: {
   allowFrom: Array<string | number>;
   senderId: string;
+  senderIds?: Array<string | null | undefined>;
   senderName?: string | null;
 }): FeishuAllowlistMatch {
-  return resolveAllowlistMatchSimple(params);
+  const allowFrom = params.allowFrom
+    .map((entry) => normalizeFeishuAllowEntry(String(entry)))
+    .filter(Boolean);
+  if (allowFrom.length === 0) {
+    return { allowed: false };
+  }
+  if (allowFrom.includes("*")) {
+    return { allowed: true, matchKey: "*", matchSource: "wildcard" };
+  }
+
+  // Feishu allowlists are ID-based; mutable display names must never grant access.
+  const senderCandidates = [params.senderId, ...(params.senderIds ?? [])]
+    .map((entry) => normalizeFeishuAllowEntry(String(entry ?? "")))
+    .filter(Boolean);
+
+  for (const senderId of senderCandidates) {
+    if (allowFrom.includes(senderId)) {
+      return { allowed: true, matchKey: senderId, matchSource: "id" };
+    }
+  }
+
+  return { allowed: false };
 }
 
 export function resolveFeishuGroupConfig(params: {
@@ -56,6 +91,7 @@ export function isFeishuGroupAllowed(params: {
   groupPolicy: "open" | "allowlist" | "disabled";
   allowFrom: Array<string | number>;
   senderId: string;
+  senderIds?: Array<string | null | undefined>;
   senderName?: string | null;
 }): boolean {
   const { groupPolicy } = params;