New user replying after topic is closed

[wisewords (Fersion)]

I believe there’s a bug that would affect the forum (I use) in the future, and it’s this bug.

This new user was able to add a new post to a topic that was closed 8 hours ago.
They were not granted admin, mod, or tl4; they’re just a simple new user.
(I am unable to post the user’s badges because i’m currently a new user here.)
The post the new user made also got bumped, causing other users (in a seperate forum) wondering how this happened.
A lot of people say it’s probably “just someone using some code to reply”, but I believe this is a bug that can affect a lot of discourse forums later on.
We currently use forum version 3.3.0.beta6.

Will this be fixed in the near future?

[sam (Sam Saffron)]

This should certainly never happen, are you able to reproduce this consistently?

[ondrej]

Could it be that their post was in the review queue and then approved after the topic was closed? I’m not sure if that is a ‘thing’ anymore but I’ve seen this happen before over at Infinite Flight Community a year ago or so.

[Arkshine]

I think you nailed it, ondrej.
If a moderator approves a post on a closed topic, you will be asked if you still want to create the post:

Then it happens:

[ondrej]

Thanks for testing!