Love custom fonts on your Galaxy phone? Don’t download the March 2026 update.

Like many Android OEMs, Samsung lets you switch to custom fonts on your phone. This is great if you’re not feeling the default font styles for some reason or if you simply want a fresh look. Unfortunately, it sounds like a recent update is breaking this functionality.

Samsung owners on Reddit (1, 2) have reported that they effectively lost custom fonts after updating to the March 2026 security patch. The issue seems to affect users on both One UI 8.5 and One UI 8.

Affected users found that they couldn’t switch to a custom font. Furthermore, some users found that switching from a custom font to another font rendered the initial custom font unusable. Galaxy owners also reported seeing an error message, as seen in the screenshot below.

“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,” reads a description of the vulnerability and fix.

The good news is that custom fonts aren’t completely ruined, as custom fonts obtained from the Galaxy Store still apparently work fine. However, this is far from ideal as plenty of custom fonts aren’t available via the Galaxy Store in the first place. For instance, some affected Galaxy owners were using the zfont 3 app. The zfont 3 developer has indeed confirmed that Samsung’s recent update patched the flaw they were using to “bypass font restrictions.”

We’ve asked Samsung’s US and UK representatives for comment and will update the article as soon as they respond to our queries. Either way, it would be a shame if custom fonts couldn’t be downloaded and installed from third-party sources. So you might want to hold off on the March 2026 update for now if you haven’t installed it yet.