diff --git a/shared/util/fileUtil.ts b/shared/util/fileUtil.ts
index 71601a90db..c5aacd8a0d 100644
--- a/shared/util/fileUtil.ts
+++ b/shared/util/fileUtil.ts
@@ -32,10 +32,18 @@ export async function loadFileBuffer(requireUrl: {
     // in vitest, this is the url we need to load with readfilesync
     // eslint-disable-next-line
     const fs = require("fs");
-    let url = requireUrl.default;
-
-    if (url.startsWith("/@fs/")) {
-      url = url.substring("/@fs".length);
+    // Direct paths can contain literal percent sequences. Prefer an existing
+    // path, then decode Vite's /@fs and encoded absolute asset URLs.
+    const assetPath = requireUrl.default;
+    let url = assetPath;
+    if (assetPath.startsWith("/@fs/")) {
+      url = decodeURIComponent(assetPath.substring("/@fs".length));
+    } else if (!fs.existsSync(assetPath)) {
+      try {
+        url = decodeURIComponent(assetPath);
+      } catch {
+        // Preserve a malformed percent sequence as a literal filesystem path.
+      }
     }
     // On Windows, vite/vitest may yield paths like "/C:/..." after removing /@fs
     // Node on Windows treats paths starting with "/" as relative to current drive,
diff --git a/tests/src/unit/shared/fileUtil.test.ts b/tests/src/unit/shared/fileUtil.test.ts
new file mode 100644
index 0000000000..e1a009975e
--- /dev/null
+++ b/tests/src/unit/shared/fileUtil.test.ts
@@ -0,0 +1,63 @@
+import { loadFileBuffer, loadFontDataUrl } from "@shared/util/fileUtil.js";
+import { mkdtempSync, rmSync, writeFileSync } from "node:fs";
+import { tmpdir } from "node:os";
+import { join } from "node:path";
+import { pathToFileURL } from "node:url";
+import { afterEach, beforeEach, describe, expect, it } from "vite-plus/test";
+
+describe("Vite asset file loading", () => {
+  let directory: string;
+  const contents = Buffer.from([0, 127, 128, 255]);
+
+  beforeEach(() => {
+    directory = mkdtempSync(join(tmpdir(), "blocknote-file-url-"));
+  });
+
+  afterEach(() => {
+    rmSync(directory, { recursive: true, force: true });
+  });
+
+  for (const prefix of ["", "/@fs"]) {
+    it.each(["한글 font.ttf", "font #100% %20.ttf"])(
+      `reads encoded ${prefix || "absolute"} asset paths: %s`,
+      async (name) => {
+        const file = join(directory, name);
+        writeFileSync(file, contents);
+
+        const buffer = await loadFileBuffer({
+          default: prefix + pathToFileURL(file).pathname,
+        });
+
+        expect(buffer).toEqual(contents);
+      },
+    );
+  }
+
+  it("reads an unencoded filesystem path", async () => {
+    const file = join(directory, "font.ttf");
+    writeFileSync(file, contents);
+
+    expect(await loadFileBuffer({ default: file })).toEqual(contents);
+  });
+
+  it.each(["font%20.ttf", "font%foo.ttf"])(
+    "preserves a direct filesystem path containing %s",
+    async (name) => {
+      const file = join(directory, name);
+      writeFileSync(file, contents);
+
+      expect(await loadFileBuffer({ default: file })).toEqual(contents);
+    },
+  );
+
+  it("creates a font data URL from an encoded asset path", async () => {
+    const file = join(directory, "한글 font.ttf");
+    writeFileSync(file, contents);
+
+    expect(
+      await loadFontDataUrl({
+        default: "/@fs" + pathToFileURL(file).pathname,
+      }),
+    ).toBe(`data:font/ttf;base64,${contents.toString("base64")}`);
+  });
+});