Bleeding Pipe: A RCE vulnerability exploited in the wild

BleedingPipe is an exploit being used in the wild allowing FULL remote code execution on clients and servers running popular Minecraft mods on 1.7.10/1.12.2 Forge (its mainly those versions, other versions are affected.), alongside some other mods. Use of the BleedingPipe exploit has already been observed on unsuspecting servers.

This is a vulnerability in mods using unsafe deserialization code, not in Forge itself.