There was an article published on Cointelegraph six hours ago with a very interesting title with definitely looks like a clickbait title: What security? Bitcoin enthusiast cracks known 12-word seed phrase in minutes
So, here is the deal. One person posted all the 12 words of his wallet in no particular order. This wallet was filled with 100,000 satoshis. Long story short, it took 25 minutes to one person with modern GPU to bruteforce the wallet by using the software called BTCrecover.

There are people who think that its okay to not completely hide your seeds if you remember the way they are ordered but this small experiment makes it pretty clear that one should be more cautious.

Otherwise, your 12-word seed phrase is as safe as 24-word seed phrase if attacker doesn't know your seeds. But if one knows seeds but not their ordering, then 12-word seed wallet will be vulnerable to attacks but 24-word seed phrase still maintains high security.