Vue version

3.5.22

Link to minimal reproduction

https://gist.github.com/syimyuzya/05412cc74587b2b31f935c9db9c0ee8a

Steps to reproduce

Open the reproduction example HTML file in a browser, no build process needed.

What is expected?

A page showing the following text:

Fail #1: param is orz

Pass #1: param is orz

Pass #2: param is orz

What is actually happening?

Got a TypeError: can't access property "type", value is undefined

System Info

System:
    OS: Linux 6.16 Arch Linux
    CPU: (8) x64 11th Gen Intel(R) Core(TM) i7-1165G7 @ 2.80GHz
    Memory: 6.68 GB / 15.35 GB
    Container: Yes
    Shell: 5.9 - /usr/bin/zsh
  Binaries:
    Node: 24.8.0 - /usr/bin/node
    Yarn: 1.22.22 - ~/.local/bin/yarn
    npm: 11.6.0 - /usr/bin/npm
    pnpm: 9.4.0 - ~/.local/bin/pnpm
    bun: 1.2.14 - ~/.bun/bin/bun

Any additional comments?

The problem only occurs in in-DOM templates. SFCs and <script type="text/x-template"> is unaffected and work just fine.