diff --git a/src/auto-reply/reply/agent-runner-payloads.test.ts b/src/auto-reply/reply/agent-runner-payloads.test.ts
index e067b01a589..94088b2b5b8 100644
--- a/src/auto-reply/reply/agent-runner-payloads.test.ts
+++ b/src/auto-reply/reply/agent-runner-payloads.test.ts
@@ -58,6 +58,35 @@ describe("buildReplyPayloads media filter integration", () => {
     });
   });
 
+  it("drops only invalid media when reply media normalization fails", async () => {
+    const normalizeMediaPaths = async (payload: { mediaUrl?: string }) => {
+      if (payload.mediaUrl === "./bad.png") {
+        throw new Error("Path escapes sandbox root");
+      }
+      return payload;
+    };
+
+    const { replyPayloads } = await buildReplyPayloads({
+      ...baseParams,
+      payloads: [
+        { text: "keep text", mediaUrl: "./bad.png", audioAsVoice: true },
+        { text: "keep second" },
+      ],
+      normalizeMediaPaths,
+    });
+
+    expect(replyPayloads).toHaveLength(2);
+    expect(replyPayloads[0]).toMatchObject({
+      text: "keep text",
+      mediaUrl: undefined,
+      mediaUrls: undefined,
+      audioAsVoice: false,
+    });
+    expect(replyPayloads[1]).toMatchObject({
+      text: "keep second",
+    });
+  });
+
   it("applies media filter after text filter", async () => {
     const { replyPayloads } = await buildReplyPayloads({
       ...baseParams,
diff --git a/src/auto-reply/reply/agent-runner-payloads.ts b/src/auto-reply/reply/agent-runner-payloads.ts
index 8ed02bdf454..263dea9fd54 100644
--- a/src/auto-reply/reply/agent-runner-payloads.ts
+++ b/src/auto-reply/reply/agent-runner-payloads.ts
@@ -20,6 +20,31 @@ import {
   shouldSuppressMessagingToolReplies,
 } from "./reply-payloads.js";
 
+function hasPayloadMedia(payload: ReplyPayload): boolean {
+  return Boolean(payload.mediaUrl) || (payload.mediaUrls?.length ?? 0) > 0;
+}
+
+async function normalizeReplyPayloadMedia(params: {
+  payload: ReplyPayload;
+  normalizeMediaPaths?: (payload: ReplyPayload) => Promise<ReplyPayload>;
+}): Promise<ReplyPayload> {
+  if (!params.normalizeMediaPaths || !hasPayloadMedia(params.payload)) {
+    return params.payload;
+  }
+
+  try {
+    return await params.normalizeMediaPaths(params.payload);
+  } catch (err) {
+    logVerbose(`reply payload media normalization failed: ${String(err)}`);
+    return {
+      ...params.payload,
+      mediaUrl: undefined,
+      mediaUrls: undefined,
+      audioAsVoice: false,
+    };
+  }
+}
+
 async function normalizeSentMediaUrlsForDedupe(params: {
   sentMediaUrls: string[];
   normalizeMediaPaths?: (payload: ReplyPayload) => Promise<ReplyPayload>;
@@ -126,7 +151,10 @@ export async function buildReplyPayloads(params: {
           silentToken: SILENT_REPLY_TOKEN,
           parseMode: "always",
         }).payload;
-        return params.normalizeMediaPaths ? await params.normalizeMediaPaths(parsed) : parsed;
+        return await normalizeReplyPayloadMedia({
+          payload: parsed,
+          normalizeMediaPaths: params.normalizeMediaPaths,
+        });
       }),
     )
   ).filter(isRenderablePayload);