diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index f0266c72174..8de4f3882c8 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -259,6 +259,9 @@ jobs:
       - name: Check types and lint and oxfmt
         run: pnpm check
 
+      - name: Enforce safe external URL opening policy
+        run: pnpm lint:ui:no-raw-window-open
+
   # Report-only dead-code scans. Runs after scope detection and stores machine-readable
   # results as artifacts for later triage before we enable hard gates.
   # Temporarily disabled in CI while we process initial findings.
diff --git a/ui/src/ui/open-external-url.test.ts b/ui/src/ui/open-external-url.test.ts
index 8972516ed57..fb3f15d88d9 100644
--- a/ui/src/ui/open-external-url.test.ts
+++ b/ui/src/ui/open-external-url.test.ts
@@ -1,5 +1,10 @@
-import { describe, expect, it } from "vitest";
-import { resolveSafeExternalUrl } from "./open-external-url.ts";
+import { afterEach, describe, expect, it, vi } from "vitest";
+import { openExternalUrlSafe, resolveSafeExternalUrl } from "./open-external-url.ts";
+
+afterEach(() => {
+  vi.restoreAllMocks();
+  vi.unstubAllGlobals();
+});
 
 describe("resolveSafeExternalUrl", () => {
   const baseHref = "https://openclaw.ai/chat";
@@ -38,6 +43,18 @@ describe("resolveSafeExternalUrl", () => {
     ).toBeNull();
   });
 
+  it("rejects SVG data image URLs", () => {
+    expect(
+      resolveSafeExternalUrl(
+        "data:image/svg+xml,<svg xmlns='http://www.w3.org/2000/svg' />",
+        baseHref,
+        {
+          allowDataImage: true,
+        },
+      ),
+    ).toBeNull();
+  });
+
   it("rejects data image URLs unless explicitly enabled", () => {
     expect(resolveSafeExternalUrl("data:image/png;base64,iVBORw0KGgo=", baseHref)).toBeNull();
   });
@@ -54,3 +71,26 @@ describe("resolveSafeExternalUrl", () => {
     expect(resolveSafeExternalUrl("   ", baseHref)).toBeNull();
   });
 });
+
+describe("openExternalUrlSafe", () => {
+  it("nulls opener when window.open returns a proxy-like object", () => {
+    const openedLikeProxy = {
+      opener: { postMessage: () => void 0 },
+    } as unknown as WindowProxy;
+    const openMock = vi.fn(() => openedLikeProxy);
+    vi.stubGlobal("window", {
+      location: { href: "https://openclaw.ai/chat" },
+      open: openMock,
+    } as unknown as Window & typeof globalThis);
+
+    const opened = openExternalUrlSafe("https://example.com/safe.png");
+
+    expect(openMock).toHaveBeenCalledWith(
+      "https://example.com/safe.png",
+      "_blank",
+      "noopener,noreferrer",
+    );
+    expect(opened).toBe(openedLikeProxy);
+    expect(openedLikeProxy.opener).toBeNull();
+  });
+});
diff --git a/ui/src/ui/open-external-url.ts b/ui/src/ui/open-external-url.ts
index 321e69a71fc..ed5a99c8678 100644
--- a/ui/src/ui/open-external-url.ts
+++ b/ui/src/ui/open-external-url.ts
@@ -1,5 +1,6 @@
 const DATA_URL_PREFIX = "data:";
 const ALLOWED_EXTERNAL_PROTOCOLS = new Set(["http:", "https:", "blob:"]);
+const BLOCKED_DATA_IMAGE_MIME_TYPES = new Set(["image/svg+xml"]);
 
 function isAllowedDataImageUrl(url: string): boolean {
   if (!url.toLowerCase().startsWith(DATA_URL_PREFIX)) {
@@ -13,7 +14,11 @@ function isAllowedDataImageUrl(url: string): boolean {
 
   const metadata = url.slice(DATA_URL_PREFIX.length, commaIndex);
   const mimeType = metadata.split(";")[0]?.trim().toLowerCase() ?? "";
-  return mimeType.startsWith("image/");
+  if (!mimeType.startsWith("image/")) {
+    return false;
+  }
+
+  return !BLOCKED_DATA_IMAGE_MIME_TYPES.has(mimeType);
 }
 
 export type ResolveSafeExternalUrlOptions = {
diff --git a/ui/src/ui/views/chat-image-open.browser.test.ts b/ui/src/ui/views/chat-image-open.browser.test.ts
index 60e6df26554..9f2090a139b 100644
--- a/ui/src/ui/views/chat-image-open.browser.test.ts
+++ b/ui/src/ui/views/chat-image-open.browser.test.ts
@@ -50,4 +50,21 @@ describe("chat image open safety", () => {
 
     expect(openSpy).not.toHaveBeenCalled();
   });
+
+  it("does not open SVG data image URLs", async () => {
+    const app = mountApp("/chat");
+    await app.updateComplete;
+
+    const openSpy = vi.spyOn(window, "open").mockReturnValue(null);
+    app.chatMessages = [
+      renderAssistantImage("data:image/svg+xml,<svg xmlns='http://www.w3.org/2000/svg' />"),
+    ];
+    await app.updateComplete;
+
+    const image = app.querySelector<HTMLImageElement>(".chat-message-image");
+    expect(image).not.toBeNull();
+    image?.dispatchEvent(new MouseEvent("click", { bubbles: true }));
+
+    expect(openSpy).not.toHaveBeenCalled();
+  });
 });