fix: harden discord and slack reaction ingress authorization

2026-02-26 01:26:37 +01:00
parent c736f11a16
commit aedf62ac7e
8 changed files with 483 additions and 5 deletions
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -14,6 +14,7 @@ Docs: https://docs.openclaw.ai

 - Slack/Session threads: prevent oversized parent-session inheritance from silently bricking new thread sessions, surface embedded context-overflow empty-result failures to users, and add configurable `session.parentForkMaxTokens` (default `100000`, `0` disables). (#26912) Thanks @markshields-tl.
 - Security/Signal: enforce DM/group authorization before reaction-only notification enqueue so unauthorized senders can no longer inject Signal reaction system events under `dmPolicy`/`groupPolicy`; reaction notifications now require channel access checks first. This ships in the next npm release (`2026.2.25`). Thanks @tdjackey for reporting.
+- Security/Discord + Slack reactions: enforce DM policy/allowlist authorization before reaction-event system enqueue in direct messages; Discord reaction handling now also honors DM/group-DM enablement and guild `groupPolicy` channel gating to keep reaction ingress aligned with normal message preflight. This ships in the next npm release (`2026.2.25`). Thanks @tdjackey for reporting.
 - Security/Telegram reactions: enforce `dmPolicy`/`allowFrom` and group allowlist authorization on `message_reaction` events before enqueueing reaction system events, preventing unauthorized reaction-triggered input in DMs and groups; ships in the next npm release (`2026.2.25`). Thanks @tdjackey for reporting.
 - Security/macOS beta onboarding: remove Anthropic OAuth sign-in and the legacy `oauth.json` onboarding path that exposed the PKCE verifier via OAuth `state`; this impacted the macOS beta onboarding path only. Anthropic subscription auth is now setup-token-only and will ship in the next npm release (`2026.2.25`). Thanks @zdi-disclosures for reporting.
 - Security/Nextcloud Talk: drop replayed signed webhook events with persistent per-account replay dedupe across restarts, and reject unexpected webhook backend origins when account base URL is configured. Thanks @aristorechina for reporting.
--- a/src/discord/monitor.test.ts
+++ b/src/discord/monitor.test.ts
@@ -1,5 +1,5 @@
 import { ChannelType, type Guild } from "@buape/carbon";
-import { describe, expect, it, vi } from "vitest";
+import { beforeEach, describe, expect, it, vi } from "vitest";
 import { typedCases } from "../test-utils/typed-cases.js";
 import {
  allowListMatches,
@@ -20,6 +20,12 @@ import {
 } from "./monitor.js";
 import { DiscordMessageListener, DiscordReactionListener } from "./monitor/listeners.js";

+const readAllowFromStoreMock = vi.hoisted(() => vi.fn());
+
+vi.mock("../pairing/pairing-store.js", () => ({
+  readChannelAllowFromStore: (...args: unknown[]) => readAllowFromStoreMock(...args),
+}));
+
 const fakeGuild = (id: string, name: string) => ({ id, name }) as Guild;

 const makeEntries = (
@@ -899,6 +905,12 @@ function makeReactionClient(options?: {

 function makeReactionListenerParams(overrides?: {
  botUserId?: string;
+  dmEnabled?: boolean;
+  groupDmEnabled?: boolean;
+  groupDmChannels?: string[];
+  dmPolicy?: "open" | "pairing" | "allowlist" | "disabled";
+  allowFrom?: string[];
+  groupPolicy?: "open" | "allowlist" | "disabled";
  allowNameMatching?: boolean;
  guildEntries?: Record<string, DiscordGuildEntryResolved>;
 }) {
@@ -907,6 +919,12 @@ function makeReactionListenerParams(overrides?: {
    accountId: "acc-1",
    runtime: {} as import("../runtime.js").RuntimeEnv,
    botUserId: overrides?.botUserId ?? "bot-1",
+    dmEnabled: overrides?.dmEnabled ?? true,
+    groupDmEnabled: overrides?.groupDmEnabled ?? true,
+    groupDmChannels: overrides?.groupDmChannels ?? [],
+    dmPolicy: overrides?.dmPolicy ?? "open",
+    allowFrom: overrides?.allowFrom ?? [],
+    groupPolicy: overrides?.groupPolicy ?? "open",
    allowNameMatching: overrides?.allowNameMatching ?? false,
    guildEntries: overrides?.guildEntries,
    logger: {
@@ -919,6 +937,12 @@ function makeReactionListenerParams(overrides?: {
 }

 describe("discord DM reaction handling", () => {
+  beforeEach(() => {
+    enqueueSystemEventSpy.mockClear();
+    resolveAgentRouteMock.mockClear();
+    readAllowFromStoreMock.mockReset().mockResolvedValue([]);
+  });
+
  it("processes DM reactions with or without guild allowlists", async () => {
    const cases = [
      { name: "no guild allowlist", guildEntries: undefined },
@@ -952,9 +976,77 @@ describe("discord DM reaction handling", () => {
    }
  });

+  it("blocks DM reactions when dmPolicy is disabled", async () => {
+    const data = makeReactionEvent({ botAsAuthor: true });
+    const client = makeReactionClient({ channelType: ChannelType.DM });
+    const listener = new DiscordReactionListener(
+      makeReactionListenerParams({ dmPolicy: "disabled" }),
+    );
+
+    await listener.handle(data, client);
+
+    expect(enqueueSystemEventSpy).not.toHaveBeenCalled();
+  });
+
+  it("blocks DM reactions for unauthorized sender in allowlist mode", async () => {
+    const data = makeReactionEvent({ botAsAuthor: true, userId: "user-1" });
+    const client = makeReactionClient({ channelType: ChannelType.DM });
+    const listener = new DiscordReactionListener(
+      makeReactionListenerParams({
+        dmPolicy: "allowlist",
+        allowFrom: ["user:user-2"],
+      }),
+    );
+
+    await listener.handle(data, client);
+
+    expect(enqueueSystemEventSpy).not.toHaveBeenCalled();
+  });
+
+  it("allows DM reactions for authorized sender in allowlist mode", async () => {
+    const data = makeReactionEvent({ botAsAuthor: true, userId: "user-1" });
+    const client = makeReactionClient({ channelType: ChannelType.DM });
+    const listener = new DiscordReactionListener(
+      makeReactionListenerParams({
+        dmPolicy: "allowlist",
+        allowFrom: ["user:user-1"],
+      }),
+    );
+
+    await listener.handle(data, client);
+
+    expect(enqueueSystemEventSpy).toHaveBeenCalledOnce();
+  });
+
+  it("blocks group DM reactions when group DMs are disabled", async () => {
+    const data = makeReactionEvent({ botAsAuthor: true });
+    const client = makeReactionClient({ channelType: ChannelType.GroupDM });
+    const listener = new DiscordReactionListener(
+      makeReactionListenerParams({ groupDmEnabled: false }),
+    );
+
+    await listener.handle(data, client);
+
+    expect(enqueueSystemEventSpy).not.toHaveBeenCalled();
+  });
+
+  it("blocks guild reactions when groupPolicy is disabled", async () => {
+    const data = makeReactionEvent({
+      guildId: "guild-123",
+      botAsAuthor: true,
+      guild: { id: "guild-123", name: "Guild" },
+    });
+    const client = makeReactionClient({ channelType: ChannelType.GuildText });
+    const listener = new DiscordReactionListener(
+      makeReactionListenerParams({ groupPolicy: "disabled" }),
+    );
+
+    await listener.handle(data, client);
+
+    expect(enqueueSystemEventSpy).not.toHaveBeenCalled();
+  });
+
  it("still processes guild reactions (no regression)", async () => {
-    enqueueSystemEventSpy.mockClear();
-    resolveAgentRouteMock.mockClear();
    resolveAgentRouteMock.mockReturnValueOnce({
      agentId: "default",
      channel: "discord",
--- a/src/discord/monitor/listeners.ts
+++ b/src/discord/monitor/listeners.ts
@@ -7,14 +7,20 @@ import {
  PresenceUpdateListener,
  type User,
 } from "@buape/carbon";
-import { danger } from "../../globals.js";
+import { danger, logVerbose } from "../../globals.js";
 import { formatDurationSeconds } from "../../infra/format-time/format-duration.ts";
 import { enqueueSystemEvent } from "../../infra/system-events.js";
 import { createSubsystemLogger } from "../../logging/subsystem.js";
+import { readChannelAllowFromStore } from "../../pairing/pairing-store.js";
 import { resolveAgentRoute } from "../../routing/resolve-route.js";
+import { resolveDmGroupAccessWithLists } from "../../security/dm-policy-shared.js";
 import {
+  isDiscordGroupAllowedByPolicy,
+  normalizeDiscordAllowList,
  normalizeDiscordSlug,
+  resolveDiscordAllowListMatch,
  resolveDiscordChannelConfigWithFallback,
+  resolveGroupDmAllow,
  resolveDiscordGuildEntry,
  shouldEmitDiscordReactionNotification,
 } from "./allow-list.js";
@@ -37,6 +43,12 @@ type DiscordReactionListenerParams = {
  accountId: string;
  runtime: RuntimeEnv;
  botUserId?: string;
+  dmEnabled: boolean;
+  groupDmEnabled: boolean;
+  groupDmChannels: string[];
+  dmPolicy: "open" | "pairing" | "allowlist" | "disabled";
+  allowFrom: string[];
+  groupPolicy: "open" | "allowlist" | "disabled";
  allowNameMatching: boolean;
  guildEntries?: Record<string, import("./allow-list.js").DiscordGuildEntryResolved>;
  logger: Logger;
@@ -179,6 +191,12 @@ async function runDiscordReactionHandler(params: {
        cfg: params.handlerParams.cfg,
        accountId: params.handlerParams.accountId,
        botUserId: params.handlerParams.botUserId,
+        dmEnabled: params.handlerParams.dmEnabled,
+        groupDmEnabled: params.handlerParams.groupDmEnabled,
+        groupDmChannels: params.handlerParams.groupDmChannels,
+        dmPolicy: params.handlerParams.dmPolicy,
+        allowFrom: params.handlerParams.allowFrom,
+        groupPolicy: params.handlerParams.groupPolicy,
        allowNameMatching: params.handlerParams.allowNameMatching,
        guildEntries: params.handlerParams.guildEntries,
        logger: params.handlerParams.logger,
@@ -193,6 +211,12 @@ async function handleDiscordReactionEvent(params: {
  cfg: LoadedConfig;
  accountId: string;
  botUserId?: string;
+  dmEnabled: boolean;
+  groupDmEnabled: boolean;
+  groupDmChannels: string[];
+  dmPolicy: "open" | "pairing" | "allowlist" | "disabled";
+  allowFrom: string[];
+  groupPolicy: "open" | "allowlist" | "disabled";
  allowNameMatching: boolean;
  guildEntries?: Record<string, import("./allow-list.js").DiscordGuildEntryResolved>;
  logger: Logger;
@@ -236,6 +260,12 @@ async function handleDiscordReactionEvent(params: {
      channelType === ChannelType.PublicThread ||
      channelType === ChannelType.PrivateThread ||
      channelType === ChannelType.AnnouncementThread;
+    if (isDirectMessage && !params.dmEnabled) {
+      return;
+    }
+    if (isGroupDm && !params.groupDmEnabled) {
+      return;
+    }
    let parentId = "parentId" in channel ? (channel.parentId ?? undefined) : undefined;
    let parentName: string | undefined;
    let parentSlug = "";
@@ -264,6 +294,45 @@ async function handleDiscordReactionEvent(params: {
      reactionBase = { baseText, contextKey };
      return reactionBase;
    };
+    const isDirectReactionAuthorized = async () => {
+      if (!isDirectMessage) {
+        return true;
+      }
+      const storeAllowFrom =
+        params.dmPolicy === "allowlist"
+          ? []
+          : await readChannelAllowFromStore("discord").catch(() => []);
+      const access = resolveDmGroupAccessWithLists({
+        isGroup: false,
+        dmPolicy: params.dmPolicy,
+        groupPolicy: params.groupPolicy,
+        allowFrom: params.allowFrom,
+        groupAllowFrom: [],
+        storeAllowFrom,
+        isSenderAllowed: (allowEntries) => {
+          const allowList = normalizeDiscordAllowList(allowEntries, ["discord:", "user:", "pk:"]);
+          const allowMatch = allowList
+            ? resolveDiscordAllowListMatch({
+                allowList,
+                candidate: {
+                  id: user.id,
+                  name: user.username,
+                  tag: formatDiscordUserTag(user),
+                },
+                allowNameMatching: params.allowNameMatching,
+              })
+            : { allowed: false };
+          return allowMatch.allowed;
+        },
+      });
+      if (access.decision !== "allow") {
+        logVerbose(
+          `discord reaction blocked sender=${user.id} (dmPolicy=${params.dmPolicy}, decision=${access.decision}, reason=${access.reason})`,
+        );
+        return false;
+      }
+      return true;
+    };
    const emitReaction = (text: string, parentPeerId?: string) => {
      const { contextKey } = resolveReactionBase();
      const route = resolveAgentRoute({
@@ -322,6 +391,44 @@ async function handleDiscordReactionEvent(params: {
        parentSlug,
        scope: "thread",
      });
+    const isGuildReactionAllowed = (channelConfig: { allowed?: boolean } | null) => {
+      if (!isGuildMessage) {
+        return true;
+      }
+      const channelAllowlistConfigured =
+        Boolean(guildInfo?.channels) && Object.keys(guildInfo?.channels ?? {}).length > 0;
+      const channelAllowed = channelConfig?.allowed !== false;
+      if (
+        !isDiscordGroupAllowedByPolicy({
+          groupPolicy: params.groupPolicy,
+          guildAllowlisted: Boolean(guildInfo),
+          channelAllowlistConfigured,
+          channelAllowed,
+        })
+      ) {
+        return false;
+      }
+      if (channelConfig?.allowed === false) {
+        return false;
+      }
+      return true;
+    };
+
+    if (!(await isDirectReactionAuthorized())) {
+      return;
+    }
+
+    if (
+      isGroupDm &&
+      !resolveGroupDmAllow({
+        channels: params.groupDmChannels,
+        channelId: data.channel_id,
+        channelName,
+        channelSlug,
+      })
+    ) {
+      return;
+    }

    // Parallelize async operations for thread channels
    if (isThreadChannel) {
@@ -370,6 +477,9 @@ async function handleDiscordReactionEvent(params: {
      if (channelConfig?.allowed === false) {
        return;
      }
+      if (!isGuildReactionAllowed(channelConfig)) {
+        return;
+      }

      const messageAuthorId = message?.author?.id ?? undefined;
      if (!shouldNotifyReaction({ mode: reactionMode, messageAuthorId })) {
@@ -394,6 +504,9 @@ async function handleDiscordReactionEvent(params: {
    if (channelConfig?.allowed === false) {
      return;
    }
+    if (!isGuildReactionAllowed(channelConfig)) {
+      return;
+    }

    const reactionMode = guildInfo?.reactionNotifications ?? "own";

--- a/src/discord/monitor/provider.ts
+++ b/src/discord/monitor/provider.ts
@@ -561,6 +561,12 @@ export async function monitorDiscordProvider(opts: MonitorDiscordOpts = {}) {
        accountId: account.accountId,
        runtime,
        botUserId,
+        dmEnabled,
+        groupDmEnabled,
+        groupDmChannels: groupDmChannels ?? [],
+        dmPolicy,
+        allowFrom: allowFrom ?? [],
+        groupPolicy,
        allowNameMatching: isDangerousNameMatchingEnabled(discordCfg),
        guildEntries,
        logger,
@@ -573,6 +579,12 @@ export async function monitorDiscordProvider(opts: MonitorDiscordOpts = {}) {
        accountId: account.accountId,
        runtime,
        botUserId,
+        dmEnabled,
+        groupDmEnabled,
+        groupDmChannels: groupDmChannels ?? [],
+        dmPolicy,
+        allowFrom: allowFrom ?? [],
+        groupPolicy,
        allowNameMatching: isDangerousNameMatchingEnabled(discordCfg),
        guildEntries,
        logger,
--- a/src/security/dm-policy-shared.test.ts
+++ b/src/security/dm-policy-shared.test.ts
@@ -2,6 +2,7 @@ import { describe, expect, it } from "vitest";
 import {
  resolveDmAllowState,
  resolveDmGroupAccessDecision,
+  resolveDmGroupAccessWithLists,
  resolveEffectiveAllowFromLists,
 } from "./dm-policy-shared.js";

@@ -75,6 +76,37 @@ describe("security/dm-policy-shared", () => {
    expect(lists.effectiveGroupAllowFrom).toEqual(["+1111", "+2222"]);
  });

+  it("resolves access + effective allowlists in one shared call", () => {
+    const resolved = resolveDmGroupAccessWithLists({
+      isGroup: false,
+      dmPolicy: "pairing",
+      groupPolicy: "allowlist",
+      allowFrom: ["owner"],
+      groupAllowFrom: ["group:room"],
+      storeAllowFrom: ["paired-user"],
+      isSenderAllowed: (allowFrom) => allowFrom.includes("paired-user"),
+    });
+    expect(resolved.decision).toBe("allow");
+    expect(resolved.reason).toBe("dmPolicy=pairing (allowlisted)");
+    expect(resolved.effectiveAllowFrom).toEqual(["owner", "paired-user"]);
+    expect(resolved.effectiveGroupAllowFrom).toEqual(["group:room", "paired-user"]);
+  });
+
+  it("keeps allowlist mode strict in shared resolver (no pairing-store fallback)", () => {
+    const resolved = resolveDmGroupAccessWithLists({
+      isGroup: false,
+      dmPolicy: "allowlist",
+      groupPolicy: "allowlist",
+      allowFrom: ["owner"],
+      groupAllowFrom: [],
+      storeAllowFrom: ["paired-user"],
+      isSenderAllowed: () => false,
+    });
+    expect(resolved.decision).toBe("block");
+    expect(resolved.reason).toBe("dmPolicy=allowlist (not allowlisted)");
+    expect(resolved.effectiveAllowFrom).toEqual(["owner"]);
+  });
+
  const channels = [
    "bluebubbles",
    "imessage",
--- a/src/security/dm-policy-shared.ts
+++ b/src/security/dm-policy-shared.ts
@@ -77,6 +77,41 @@ export function resolveDmGroupAccessDecision(params: {
  return { decision: "block", reason: `dmPolicy=${dmPolicy} (not allowlisted)` };
 }

+export function resolveDmGroupAccessWithLists(params: {
+  isGroup: boolean;
+  dmPolicy?: string | null;
+  groupPolicy?: string | null;
+  allowFrom?: Array<string | number> | null;
+  groupAllowFrom?: Array<string | number> | null;
+  storeAllowFrom?: Array<string | number> | null;
+  isSenderAllowed: (allowFrom: string[]) => boolean;
+}): {
+  decision: DmGroupAccessDecision;
+  reason: string;
+  effectiveAllowFrom: string[];
+  effectiveGroupAllowFrom: string[];
+} {
+  const { effectiveAllowFrom, effectiveGroupAllowFrom } = resolveEffectiveAllowFromLists({
+    allowFrom: params.allowFrom,
+    groupAllowFrom: params.groupAllowFrom,
+    storeAllowFrom: params.storeAllowFrom,
+    dmPolicy: params.dmPolicy,
+  });
+  const access = resolveDmGroupAccessDecision({
+    isGroup: params.isGroup,
+    dmPolicy: params.dmPolicy,
+    groupPolicy: params.groupPolicy,
+    effectiveAllowFrom,
+    effectiveGroupAllowFrom,
+    isSenderAllowed: params.isSenderAllowed,
+  });
+  return {
+    ...access,
+    effectiveAllowFrom,
+    effectiveGroupAllowFrom,
+  };
+}
+
 export async function resolveDmAllowState(params: {
  provider: ChannelId;
  allowFrom?: Array<string | number> | null;
--- a/src/slack/monitor/events/reactions.test.ts
+++ b/src/slack/monitor/events/reactions.test.ts
@@ -0,0 +1,163 @@
+import { describe, expect, it, vi } from "vitest";
+import type { SlackMonitorContext } from "../context.js";
+import { registerSlackReactionEvents } from "./reactions.js";
+
+const enqueueSystemEventMock = vi.fn();
+const readAllowFromStoreMock = vi.fn();
+
+vi.mock("../../../infra/system-events.js", () => ({
+  enqueueSystemEvent: (...args: unknown[]) => enqueueSystemEventMock(...args),
+}));
+
+vi.mock("../../../pairing/pairing-store.js", () => ({
+  readChannelAllowFromStore: (...args: unknown[]) => readAllowFromStoreMock(...args),
+}));
+
+type SlackReactionHandler = (args: {
+  event: Record<string, unknown>;
+  body: unknown;
+}) => Promise<void>;
+
+function createReactionContext(overrides?: {
+  dmPolicy?: "open" | "pairing" | "allowlist" | "disabled";
+  allowFrom?: string[];
+  channelType?: "im" | "channel";
+}) {
+  let addedHandler: SlackReactionHandler | null = null;
+  let removedHandler: SlackReactionHandler | null = null;
+  const channelType = overrides?.channelType ?? "im";
+  const app = {
+    event: vi.fn((name: string, handler: SlackReactionHandler) => {
+      if (name === "reaction_added") {
+        addedHandler = handler;
+      } else if (name === "reaction_removed") {
+        removedHandler = handler;
+      }
+    }),
+  };
+  const ctx = {
+    app,
+    runtime: { error: vi.fn() },
+    dmPolicy: overrides?.dmPolicy ?? "open",
+    groupPolicy: "open",
+    allowFrom: overrides?.allowFrom ?? [],
+    allowNameMatching: false,
+    shouldDropMismatchedSlackEvent: vi.fn().mockReturnValue(false),
+    isChannelAllowed: vi.fn().mockReturnValue(true),
+    resolveChannelName: vi.fn().mockResolvedValue({
+      name: channelType === "im" ? "direct" : "general",
+      type: channelType,
+    }),
+    resolveUserName: vi.fn().mockResolvedValue({ name: "alice" }),
+    resolveSlackSystemEventSessionKey: vi.fn().mockReturnValue("agent:main:main"),
+  } as unknown as SlackMonitorContext;
+  registerSlackReactionEvents({ ctx });
+  return {
+    ctx,
+    getAddedHandler: () => addedHandler,
+    getRemovedHandler: () => removedHandler,
+  };
+}
+
+function makeReactionEvent(overrides?: { user?: string; channel?: string }) {
+  return {
+    type: "reaction_added",
+    user: overrides?.user ?? "U1",
+    reaction: "thumbsup",
+    item: {
+      type: "message",
+      channel: overrides?.channel ?? "D1",
+      ts: "123.456",
+    },
+    item_user: "UBOT",
+  };
+}
+
+describe("registerSlackReactionEvents", () => {
+  it("enqueues DM reaction system events when dmPolicy is open", async () => {
+    enqueueSystemEventMock.mockClear();
+    readAllowFromStoreMock.mockReset().mockResolvedValue([]);
+    const { getAddedHandler } = createReactionContext({ dmPolicy: "open" });
+    const addedHandler = getAddedHandler();
+    expect(addedHandler).toBeTruthy();
+
+    await addedHandler!({
+      event: makeReactionEvent(),
+      body: {},
+    });
+
+    expect(enqueueSystemEventMock).toHaveBeenCalledTimes(1);
+  });
+
+  it("blocks DM reaction system events when dmPolicy is disabled", async () => {
+    enqueueSystemEventMock.mockClear();
+    readAllowFromStoreMock.mockReset().mockResolvedValue([]);
+    const { getAddedHandler } = createReactionContext({ dmPolicy: "disabled" });
+    const addedHandler = getAddedHandler();
+    expect(addedHandler).toBeTruthy();
+
+    await addedHandler!({
+      event: makeReactionEvent(),
+      body: {},
+    });
+
+    expect(enqueueSystemEventMock).not.toHaveBeenCalled();
+  });
+
+  it("blocks DM reaction system events for unauthorized senders in allowlist mode", async () => {
+    enqueueSystemEventMock.mockClear();
+    readAllowFromStoreMock.mockReset().mockResolvedValue([]);
+    const { getAddedHandler } = createReactionContext({
+      dmPolicy: "allowlist",
+      allowFrom: ["U2"],
+    });
+    const addedHandler = getAddedHandler();
+    expect(addedHandler).toBeTruthy();
+
+    await addedHandler!({
+      event: makeReactionEvent({ user: "U1" }),
+      body: {},
+    });
+
+    expect(enqueueSystemEventMock).not.toHaveBeenCalled();
+  });
+
+  it("allows DM reaction system events for authorized senders in allowlist mode", async () => {
+    enqueueSystemEventMock.mockClear();
+    readAllowFromStoreMock.mockReset().mockResolvedValue([]);
+    const { getAddedHandler } = createReactionContext({
+      dmPolicy: "allowlist",
+      allowFrom: ["U1"],
+    });
+    const addedHandler = getAddedHandler();
+    expect(addedHandler).toBeTruthy();
+
+    await addedHandler!({
+      event: makeReactionEvent({ user: "U1" }),
+      body: {},
+    });
+
+    expect(enqueueSystemEventMock).toHaveBeenCalledTimes(1);
+  });
+
+  it("enqueues channel reaction events regardless of dmPolicy", async () => {
+    enqueueSystemEventMock.mockClear();
+    readAllowFromStoreMock.mockReset().mockResolvedValue([]);
+    const { getRemovedHandler } = createReactionContext({
+      dmPolicy: "disabled",
+      channelType: "channel",
+    });
+    const removedHandler = getRemovedHandler();
+    expect(removedHandler).toBeTruthy();
+
+    await removedHandler!({
+      event: {
+        ...makeReactionEvent({ channel: "C1" }),
+        type: "reaction_removed",
+      },
+      body: {},
+    });
+
+    expect(enqueueSystemEventMock).toHaveBeenCalledTimes(1);
+  });
+});
--- a/src/slack/monitor/events/reactions.ts
+++ b/src/slack/monitor/events/reactions.ts
@@ -1,6 +1,9 @@
 import type { SlackEventMiddlewareArgs } from "@slack/bolt";
-import { danger } from "../../../globals.js";
+import { danger, logVerbose } from "../../../globals.js";
 import { enqueueSystemEvent } from "../../../infra/system-events.js";
+import { resolveDmGroupAccessWithLists } from "../../../security/dm-policy-shared.js";
+import { resolveSlackAllowListMatch } from "../allow-list.js";
+import { resolveSlackEffectiveAllowFrom } from "../auth.js";
 import { resolveSlackChannelLabel } from "../channel-config.js";
 import type { SlackMonitorContext } from "../context.js";
 import type { SlackReactionEvent } from "../types.js";
@@ -32,6 +35,33 @@ export function registerSlackReactionEvents(params: { ctx: SlackMonitorContext }
        channelName: channelInfo?.name,
      });
      const actorInfo = event.user ? await ctx.resolveUserName(event.user) : undefined;
+      if (channelType === "im") {
+        if (!event.user) {
+          return;
+        }
+        const { allowFromLower } = await resolveSlackEffectiveAllowFrom(ctx);
+        const access = resolveDmGroupAccessWithLists({
+          isGroup: false,
+          dmPolicy: ctx.dmPolicy,
+          groupPolicy: ctx.groupPolicy,
+          allowFrom: allowFromLower,
+          groupAllowFrom: [],
+          storeAllowFrom: [],
+          isSenderAllowed: (allowList) =>
+            resolveSlackAllowListMatch({
+              allowList,
+              id: event.user,
+              name: actorInfo?.name,
+              allowNameMatching: ctx.allowNameMatching,
+            }).allowed,
+        });
+        if (access.decision !== "allow") {
+          logVerbose(
+            `slack: drop reaction sender ${event.user} (dmPolicy=${ctx.dmPolicy}, decision=${access.decision}, reason=${access.reason})`,
+          );
+          return;
+        }
+      }
      const actorLabel = actorInfo?.name ?? event.user;
      const emojiLabel = event.reaction ?? "emoji";
      const authorInfo = event.item_user ? await ctx.resolveUserName(event.item_user) : undefined;