For OpenBSD patch branch information, please refer here.
Patches for the OpenBSD base system are distributed as unified diffs, which are text files that hold differences to the original source code. To apply a patch, you must have the source code from the -release version of your system available. Each patch is cryptographically signed with the signify(1) tool and contains instructions on how to apply it properly.
For errata on a certain release, click below:
2.1,
2.2,
2.3,
2.4,
2.5,
2.6,
2.7,
2.8,
2.9,
3.0,
3.1,
3.2,
3.3,
3.4,
3.5,
3.6,
3.7,
3.8,
3.9,
4.0,
4.1,
4.2,
4.3,
4.4,
4.5,
4.6,
4.7,
4.8,
4.9,
5.0,
5.1,
5.2,
5.3,
5.4,
5.5,
5.6,
5.7,
5.8,
5.9,
6.0.