Samsung's march update blocks third-party fonts on galaxy phones

Samsung's latest security patch is causing trouble for Galaxy phone owners who like to customize their device's font with third-party apps.

Samsung closes font installation backdoor

Users on Reddit started reporting that their custom fonts stopped working after installing the March 2026 update, which affects both One UI 8.5 and One UI 8 software versions.

Some can no longer switch to a custom font at all, while others found that attempting to change fonts made the one they were using unusable, with error messages popping up.

After digging into what Samsung changed, PiunikaWeb found the company patched a security flaw (CVE-2026-20989) tied to how fonts get installed on Galaxy phones.

In essence, there was a backdoor in Samsung's font installation process that third-party font apps were exploiting to let users install fonts Samsung hadn't officially approved.

This update closed that door, intentionally tightening things up and catching custom font apps in the crossfire.

Galaxy Store fonts should still work fine, but for those who've been accessing a wider variety of fonts through third-party apps, they're out of luck for now.

This is a tough pill for many Galaxy fans to swallow, as one of Android's key advantages over iPhones has always been the freedom to make your phone truly yours.

While Samsung made the safe call in securing its devices, the way it handled this update – with no warning – resulted in users waking up to broken fonts and confusing error messages.

For now, Galaxy users who want to personalize their fonts will need to go about it the official way, through Samsung's own app store.