diff --git a/src/infra/clawhub.ts b/src/infra/clawhub.ts
index d9de71fa78c2..e056cf160b0c 100644
--- a/src/infra/clawhub.ts
+++ b/src/infra/clawhub.ts
@@ -1385,7 +1385,6 @@ export async function downloadClawHubPackageArchive(params: {
     const target = await createTempDownloadTarget({
       prefix: "openclaw-clawhub-clawpack",
       fileName: npmTarballName,
-      tmpDir: os.tmpdir(),
     });
     await fs.writeFile(target.path, bytes);
     return {
@@ -1428,7 +1427,6 @@ export async function downloadClawHubPackageArchive(params: {
   const target = await createTempDownloadTarget({
     prefix: "openclaw-clawhub-package",
     fileName: `${params.name}.zip`,
-    tmpDir: os.tmpdir(),
   });
   await fs.writeFile(target.path, bytes);
   return {
@@ -1475,7 +1473,6 @@ export async function downloadClawHubSkillArchive(params: {
   const target = await createTempDownloadTarget({
     prefix: "openclaw-clawhub-skill",
     fileName: `${params.slug}.zip`,
-    tmpDir: os.tmpdir(),
   });
   await fs.writeFile(target.path, bytes);
   return {
@@ -1518,7 +1515,6 @@ export async function downloadClawHubSkillArchiveUrl(params: {
   const target = await createTempDownloadTarget({
     prefix: "openclaw-clawhub-skill",
     fileName: "skill.zip",
-    tmpDir: os.tmpdir(),
   });
   await fs.writeFile(target.path, bytes);
   return {
@@ -1555,7 +1551,6 @@ export async function downloadClawHubGitHubSkillArchive(params: {
   const target = await createTempDownloadTarget({
     prefix: "openclaw-clawhub-github-skill",
     fileName: `${params.commit}.zip`,
-    tmpDir: os.tmpdir(),
   });
   await fs.writeFile(target.path, bytes);
   return {
diff --git a/src/infra/install-source-utils.chmod.test.ts b/src/infra/install-source-utils.chmod.test.ts
new file mode 100644
index 000000000000..5b64e65fc891
--- /dev/null
+++ b/src/infra/install-source-utils.chmod.test.ts
@@ -0,0 +1,57 @@
+import fs from "node:fs/promises";
+import path from "node:path";
+import { afterEach, describe, expect, it, vi } from "vitest";
+import { useAutoCleanupTempDirTracker } from "../../test/helpers/temp-dir.js";
+
+const resolvePreferredOpenClawTmpDirMock = vi.hoisted(() => vi.fn());
+
+vi.mock("./tmp-openclaw-dir.js", async (importOriginal) => {
+  const actual = await importOriginal<typeof import("./tmp-openclaw-dir.js")>();
+  return {
+    ...actual,
+    resolvePreferredOpenClawTmpDir: resolvePreferredOpenClawTmpDirMock,
+  };
+});
+
+import { withTempDir } from "./install-source-utils.js";
+
+describe("withTempDir private root", () => {
+  const tempDirs = useAutoCleanupTempDirTracker(afterEach);
+
+  it.runIf(process.platform !== "win32")(
+    "preserves parent temp root permissions when using private OpenClaw temp root",
+    async () => {
+      const mockParentRoot = tempDirs.make("openclaw-chmod-test-");
+      const mockOpenClawDir = path.join(mockParentRoot, "openclaw");
+
+      await fs.mkdir(mockOpenClawDir, { recursive: true });
+      await fs.chmod(mockParentRoot, 0o1777);
+      const canonicalOpenClawDir = await fs.realpath(mockOpenClawDir);
+
+      resolvePreferredOpenClawTmpDirMock.mockReturnValue(mockOpenClawDir);
+
+      let observedDir = "";
+      const value = await withTempDir("openclaw-test-", async (tmpDir) => {
+        observedDir = tmpDir;
+        expect(path.dirname(tmpDir)).toBe(canonicalOpenClawDir);
+        await fs.writeFile(path.join(tmpDir, "marker.txt"), "ok");
+        return "done";
+      });
+
+      expect(value).toBe("done");
+
+      await expect(
+        fs.stat(observedDir).then(
+          () => true,
+          () => false,
+        ),
+      ).resolves.toBe(false);
+
+      const privateRootStat = await fs.stat(mockOpenClawDir);
+      expect(privateRootStat.mode & 0o7777).toBe(0o700);
+
+      const parentStat = await fs.stat(mockParentRoot);
+      expect(parentStat.mode & 0o7777).toBe(0o1777);
+    },
+  );
+});
diff --git a/src/infra/install-source-utils.ts b/src/infra/install-source-utils.ts
index 4f9474e58d95..6b77866f3ee4 100644
--- a/src/infra/install-source-utils.ts
+++ b/src/infra/install-source-utils.ts
@@ -1,6 +1,5 @@
 // Resolves and packages install sources for plugin installs.
 import fs from "node:fs/promises";
-import os from "node:os";
 import path from "node:path";
 import { isRecord } from "@openclaw/normalization-core/record-coerce";
 import { normalizeOptionalString } from "@openclaw/normalization-core/string-coerce";
@@ -11,6 +10,7 @@ import { resolveArchiveKind } from "./archive.js";
 import { pathExists } from "./fs-safe.js";
 import { applyNpmFreshnessBypassEnv, type NpmProjectInstallEnvOptions } from "./npm-install-env.js";
 import { withTempWorkspace } from "./private-temp-workspace.js";
+import { resolvePreferredOpenClawTmpDir } from "./tmp-openclaw-dir.js";
 
 /** Metadata npm reports when resolving a registry spec or packed archive. */
 export type NpmSpecResolution = {
@@ -141,7 +141,7 @@ export async function withTempDir<T>(
   fn: (tmpDir: string) => Promise<T>,
   options?: { rootDir?: string },
 ): Promise<T> {
-  const rootDir = options?.rootDir ?? os.tmpdir();
+  const rootDir = options?.rootDir ?? resolvePreferredOpenClawTmpDir();
   return await withTempWorkspace({ rootDir, prefix }, async (tmp) => fn(tmp.dir));
 }