When a Go program running on a Unix system is out of file descriptors and calls syscall.ForkExec (including indirectly by using the os/exec package), syscall.ForkExec can close file descriptor 0 as it fails. If this happens (or can be provoked) repeatedly, it can result in misdirected I/O such as writing network traffic intended for one connection to a different connection, or content intended for one file to a different one.

For users who cannot immediately update to the new release, the bug can be mitigated by raising the per-process file descriptor limit.