diff --git a/scripts/label-open-issues.ts b/scripts/label-open-issues.ts
index 8322c2889ee..02247582ad5 100644
--- a/scripts/label-open-issues.ts
+++ b/scripts/label-open-issues.ts
@@ -4,6 +4,7 @@ import { homedir } from "node:os";
 import { dirname, join } from "node:path";
 import { pathToFileURL } from "node:url";
 import { isRecord } from "../src/utils.js";
+import { readBoundedResponseText as readBoundedBodyText } from "./lib/bounded-response.ts";
 import { parseStrictIntegerOption } from "./lib/dev-tooling-safety.ts";
 
 function writeStdoutLine(message = ""): void {
@@ -22,6 +23,7 @@ const WORK_BATCH_SIZE = 500;
 const STATE_VERSION = 1;
 const DEFAULT_OPENAI_TIMEOUT_MS = 60_000;
 const OPENAI_ERROR_BODY_MAX_CHARS = 4096;
+const OPENAI_RESPONSE_BODY_MAX_BYTES = 256 * 1024;
 const STATE_FILE_NAME = "issue-labeler-state.json";
 const CONFIG_BASE_DIR = process.env.XDG_CONFIG_HOME ?? join(homedir(), ".config");
 const STATE_FILE_PATH = join(CONFIG_BASE_DIR, "openclaw", STATE_FILE_NAME);
@@ -322,6 +324,19 @@ async function readBoundedResponseText(
   return truncated ? `${text}\n[truncated]` : text;
 }
 
+async function readBoundedOpenAIJson(
+  response: Response,
+  maxBytes = OPENAI_RESPONSE_BODY_MAX_BYTES,
+): Promise<OpenAIResponse> {
+  const text = await readBoundedBodyText(response, "OpenAI classification", maxBytes, {
+    createTooLargeError: (message) =>
+      Object.assign(new Error(message), {
+        code: "ETOOBIG",
+      }),
+  });
+  return JSON.parse(text) as OpenAIResponse;
+}
+
 function logHeader(title: string) {
   writeStdoutLine(`\n${title}`);
   writeStdoutLine("=".repeat(title.length));
@@ -729,7 +744,7 @@ async function classifyItem(
         throw new Error(`OpenAI request failed (${response.status}): ${text}`);
       }
 
-      return (await response.json()) as OpenAIResponse;
+      return await readBoundedOpenAIJson(response);
     },
   );
   const rawText = extractResponseText(payload);
@@ -993,6 +1008,7 @@ async function main() {
 export const testing = {
   classifyItem,
   normalizeClassification,
+  readBoundedOpenAIJson,
   readBoundedResponseText,
   resolveOpenAITimeoutMs,
 };
diff --git a/test/scripts/label-open-issues.test.ts b/test/scripts/label-open-issues.test.ts
index 564b51dc727..993ef89e6ca 100644
--- a/test/scripts/label-open-issues.test.ts
+++ b/test/scripts/label-open-issues.test.ts
@@ -10,17 +10,16 @@ const labelItem = {
 
 describe("label-open-issues helpers", () => {
   it("classifies items from OpenAI structured response text", async () => {
-    const response = {
-      ok: true,
-      status: 200,
-      json: async () => ({
+    const response = new Response(
+      JSON.stringify({
         output_text: JSON.stringify({
           category: "bug",
           isSupport: true,
           isSkillOnly: false,
         }),
       }),
-    } as Response;
+      { status: 200 },
+    );
 
     await expect(
       testing.classifyItem(labelItem, "issue", {
@@ -55,11 +54,7 @@ describe("label-open-issues helpers", () => {
   });
 
   it("times out stalled OpenAI classification body reads", async () => {
-    const response = {
-      ok: true,
-      status: 200,
-      json: () => new Promise(() => {}),
-    } as Response;
+    const response = new Response(new ReadableStream({}), { status: 200 });
     const request = testing.classifyItem(labelItem, "issue", {
       apiKey: "test-key",
       model: "test-model",
@@ -96,6 +91,53 @@ describe("label-open-issues helpers", () => {
     expect(message.length).toBeLessThan(4300);
   });
 
+  it("reads bounded OpenAI classification JSON responses", async () => {
+    await expect(
+      testing.readBoundedOpenAIJson(new Response('{"output_text":"{}"}'), 1024),
+    ).resolves.toEqual({ output_text: "{}" });
+  });
+
+  it("rejects oversized OpenAI classification JSON responses by content length", async () => {
+    let canceled = false;
+    const response = new Response(
+      new ReadableStream({
+        cancel() {
+          canceled = true;
+        },
+      }),
+      {
+        headers: {
+          "content-length": "1025",
+        },
+      },
+    );
+
+    await expect(testing.readBoundedOpenAIJson(response, 1024)).rejects.toMatchObject({
+      code: "ETOOBIG",
+      message: "OpenAI classification response body exceeded 1024 bytes",
+    });
+    expect(canceled).toBe(true);
+  });
+
+  it("rejects oversized streamed OpenAI classification JSON responses", async () => {
+    const encoder = new TextEncoder();
+    const response = new Response(
+      new ReadableStream({
+        start(controller) {
+          controller.enqueue(encoder.encode('{"output_text":"'));
+          controller.enqueue(encoder.encode("x".repeat(1024)));
+          controller.enqueue(encoder.encode('"}'));
+          controller.close();
+        },
+      }),
+    );
+
+    await expect(testing.readBoundedOpenAIJson(response, 1024)).rejects.toMatchObject({
+      code: "ETOOBIG",
+      message: "OpenAI classification response body exceeded 1024 bytes",
+    });
+  });
+
   it("rejects invalid OpenAI classification timeout values", () => {
     expect(testing.resolveOpenAITimeoutMs("250")).toBe(250);
     expect(() => testing.resolveOpenAITimeoutMs("slow")).toThrow(