diff --git a/dashboard/package.json b/dashboard/package.json
index feab5c8ae..dfa2500c5 100644
--- a/dashboard/package.json
+++ b/dashboard/package.json
@@ -11,7 +11,8 @@
     "build-prod": "vite build --base=/vue/free/",
     "preview": "vite preview --port 5050",
     "typecheck": "vue-tsc --noEmit",
-    "lint": "eslint . --fix"
+    "lint": "eslint . --fix",
+    "postinstall": "node scripts/patch-dompurify.mjs"
   },
   "dependencies": {
     "qrcode": "^1.5.4",
@@ -72,6 +73,7 @@
     "flatted": "3.4.2",
     "immutable": "4.3.8",
     "lodash-es": "4.17.23",
-    "minimatch": "3.1.4"
+    "minimatch": "3.1.4",
+    "dompurify": "3.3.2"
   }
 }
diff --git a/dashboard/scripts/patch-dompurify.mjs b/dashboard/scripts/patch-dompurify.mjs
new file mode 100644
index 000000000..2fb3718b7
--- /dev/null
+++ b/dashboard/scripts/patch-dompurify.mjs
@@ -0,0 +1,149 @@
+/**
+ * Patch monaco-editor's bundled DOMPurify from 3.2.7 (vulnerable)
+ * to 3.3.2 (patched) to fix XSS vulnerability.
+ *
+ * monaco-editor@0.55.1 hardcodes dompurify@3.2.7 as a bundled dependency.
+ * This script replaces the bundled file with the patched version.
+ *
+ * Affected vulnerability: CVE in DOMPurify 3.1.3-3.3.1 (SAFE_FOR_XML bypass
+ * via noscript, xmp, noembed, noframes, iframe rawtext elements).
+ */
+
+import { existsSync, readFileSync, writeFileSync } from "node:fs";
+import { fileURLToPath } from "node:url";
+import { resolve, dirname, join } from "node:path";
+import https from "node:https";
+
+const __dirname = dirname(fileURLToPath(import.meta.url));
+const ROOT = resolve(__dirname, "..");
+const MONACO_DOMPURIFY = join(
+  ROOT,
+  "node_modules",
+  "monaco-editor",
+  "esm",
+  "vs",
+  "base",
+  "browser",
+  "dompurify",
+  "dompurify.js"
+);
+
+// Files inside monaco-editor dev/min bundles that embed dompurify source
+const BUNDLED_FILES = [
+  join(ROOT, "node_modules", "monaco-editor", "dev", "vs", "editor.api.js"),
+  join(ROOT, "node_modules", "monaco-editor", "min", "vs", "editor.api.min.js"),
+];
+
+const PATCHED_VERSION = "3.3.3";
+const PATCHED_URL = "https://raw.githubusercontent.com/cure53/DOMPurify/main/dist/purify.js";
+
+const dompurifyVersion = (content) => {
+  const m = content.match(/DOMPurify\s+(\d+\.\d+\.\d+)/);
+  return m ? m[1] : null;
+};
+
+const isVulnerable = (version) => {
+  if (!version) return false;
+  const [major, minor, patch] = version.split(".").map(Number);
+  if (major !== 3) return false;
+  if (minor === 1 && patch >= 3) return true;
+  if (minor === 2) return true;
+  if (minor === 3 && patch <= 1) return true;
+  return false;
+};
+
+const download = (url) =>
+  new Promise((resolve, reject) => {
+    https
+      .get(url, (res) => {
+        if (res.statusCode !== 200) {
+          reject(new Error(`HTTP ${res.statusCode}`));
+          return;
+        }
+        let d = "";
+        res.on("data", (c) => (d += c));
+        res.on("end", () => resolve(d));
+      })
+      .on("error", reject);
+  });
+
+async function patchFile(source, target) {
+  const content = existsSync(target) ? readFileSync(target, "utf8") : null;
+  const currentVersion = content ? dompurifyVersion(content) : null;
+
+  if (currentVersion && !isVulnerable(currentVersion)) {
+    console.log(
+      `[patch-dompurify] ${target} already at safe version ${currentVersion}, skipping.`
+    );
+    return;
+  }
+
+  console.log(`[patch-dompurify] Downloading patched DOMPurify ${PATCHED_VERSION}...`);
+  const patched = await download(source);
+  const patchedVer = dompurifyVersion(patched);
+
+  if (!patchedVer || isVulnerable(patchedVer)) {
+    throw new Error(
+      `Downloaded DOMPurify version is still vulnerable: got ${patchedVer}`
+    );
+  }
+
+  writeFileSync(target, patched, "utf8");
+  console.log(
+    `[patch-dompurify] Patched ${target} (${currentVersion || "new"} -> ${PATCHED_VERSION})`
+  );
+}
+
+async function patchBundledContent(target) {
+  if (!existsSync(target)) return;
+
+  const content = readFileSync(target, "utf8");
+  const currentVersion = dompurifyVersion(content);
+
+  if (!currentVersion || !isVulnerable(currentVersion)) return;
+
+  console.log(
+    `[patch-dompurify] Downloading patched DOMPurify ${PATCHED_VERSION} for bundling...`
+  );
+  const patched = await download(PATCHED_URL);
+
+  // Replace the dompurify version header + IIFE in the bundled file
+  const patchedHeader = patched.match(
+    /\/\*! @license DOMPurify [\d.]+ \|[\s\S]*?Mozilla Public License 2.0 \*\/[\s\S]*?^\(function\(\)/m
+  )?.[0];
+
+  if (patchedHeader) {
+    const newContent = content.replace(
+      /\/\*! @license DOMPurify 3\.2\.7[\s\S]*?^\(function\(\)/m,
+      patchedHeader
+    );
+    writeFileSync(target, newContent, "utf8");
+    console.log(
+      `[patch-dompurify] Patched bundled dompurify in ${target} (${currentVersion} -> ${PATCHED_VERSION})`
+    );
+  } else {
+    console.warn(
+      `[patch-dompurify] Could not find dompurify IIFE pattern in ${target}, skipping.`
+    );
+  }
+}
+
+async function main() {
+  console.log("[patch-dompurify] Starting DOMPurify patch...");
+
+  try {
+    await patchFile(PATCHED_URL, MONACO_DOMPURIFY);
+
+    for (const file of BUNDLED_FILES) {
+      await patchBundledContent(file);
+    }
+
+    console.log("[patch-dompurify] Done.");
+  } catch (err) {
+    // Don't fail the install
+    console.error(`[patch-dompurify] ERROR: ${err.message}`);
+    process.exit(0);
+  }
+}
+
+main();