Self-XSS in posts by formatting text as code

How it was found

Hi I have found an XSS in Slack. To reproduce the issue, just follow this:

1. Go to your Slack account (accountname.slack.com)

2. Below you will see a plus (+) sign, click that, there will be three options, click "Create Post"

3. You will be redirected to a page where you will create it.

4. Type the payload. I used: <svg onload=alert(domain)>. then Highlight it.. on the left side, there are symbols... click it and choose this symbol: ( <>) which is for code..

5. XSS Pop-up

Youtube video for clearer details:

https://youtu.be/dIvNeb2aRrU

THANKS!