A few days ago, researchers at midnight blue have announced a number of security vulnerabilities in TETRA and specifically the cryptography portions of it.
You can find more information at TETRA:BURST | Midnight Blue
More details shall be revealed during a series of conference talks starting from BlackHat at August 9th over Chaos Communication Camp).
It is worg noting that osmo-tetra apparently was used (and extended) for parts of this work. And not only that, wbokslag has been contributing back patches from July 2022 onwards. It’s great to see that at least some professionals in the IT security community do care about contirbuting upstream, and not just about presenting a nice talk/paper 
Some more preparatory patches are in code review right now, see https://gerrit.osmocom.org/q/owner:wbokslag if you want to follow it more closely.