Apache Commons BCEL has a number of APIs that would normally only allow changing specific class characteristics. However, due to an out-of-bounds writing issue, these APIs can be used to produce arbitrary bytecode. This could be abused in applications that pass attacker-controllable data to those APIs, giving the attacker more control over the resulting bytecode than otherwise expected. Update to Apache Commons BCEL 6.6.0.
https://security.gentoo.org/glsa/202401-25
https://lists.apache.org/thread/lfxk7q8qmnh5bt9jm6nmjlv5hsxjhrz4