-template-..-2f..-2f..-2f..-2froot-2f

It looks like you're referencing a path with directory traversal (../) that goes up multiple levels, ending in /root.

template = "templates/" + user_input + ".html"
with open(template) as f:
    return render(f.read())

3. Security Feature Analysis (Detection & Prevention)

To protect against this specific payload, applications and WAFs (Web Application Firewalls) implement several security features: -template-..-2F..-2F..-2F..-2Froot-2F

%2F (or -2F in certain filtered contexts) is the encoded forward slash /. It looks like you're referencing a path with

The string -template-..-2F..-2F..-2F..-2Froot-2F is likely a Path Traversal or Directory Traversal payload used in cybersecurity testing. -template-..-2F..-2F..-2F..-2Froot-2F