I feel like you either love custom fonts or you hate them. But this is absolutely fine, because those who love them can use them, while those who don’t, don’t have to — though I will admit a frisson of horror every time I see that Samsung font on a phone.
Unfortunately, Samsung didn’t get the memo, because it seems to have accidentally broken a bunch of custom fonts with its March security update for One UI 8 and 8.5 (via Android Authority).
Samsung patched a vital vulnerability
Security updates wouldn’t be what you’d assume would break font support, but that seems to be exactly what’s happened here. The alarm was initially raised on Reddit, when a Samsung Galaxy fan discovered that they could no longer switch to one of their custom fonts after the security update.
It seems that there are no problems if you update your phone with custom fonts enabled, and then don’t switch away from them. But if you switch away from a custom font, or try to use a new one? That’s where you’ll run into issues, based on a number of the cases we’ve seen. When trying to swap to a custom font, the hapless users were given the following message.
Credit:Â u/mixofmuri on Reddit.
So what’s going on here? It seems that the app some were using to download and install these fonts were using a particular vulnerability in Samsung’s operating system to get around some restrictions. And, well, Samsung went ahead and patched those holes in this particular update.
According to PiunikaWeb, the fix is referred to as a moderate severity concern, and the patch notes detail that “improper verification of cryptographic signature in Font Settings prior to SMR Mar-2026 Release 1 allows physical attackers to use custom font. The patch adds proper verification.”
In short, Samsung noticed that a vulnerability being used for whimsical fonts was also likely to be used by malicious actors, so they fixed the problem. You can’t blame them really, but that’s no salve for anyone who’s lost their custom fonts in the crossfire.
On the plus side, fonts installed from the Galaxy Store still work, but large numbers of fonts aren’t on the Galaxy Store, so that doesn’t help everyone.
Still, you can’t just leave legitimate security holes around just for the sake of custom fonts. If you’ve updated your phone and lost your fonts, at least you can take solace in the fact your phone is now a bit more secure.
And if you’ve updated but haven’t lost your fonts, for the love of Samsung, do not fiddle with your font settings for now.