CVE-2026-99228 is a Linux kernel vulnerability in the io_uring/io-wq subsystem where a signal that ends work can be lost. This occurs when a thread exits and its io-wq workers are signaled to exit, but some bounded work such as opening a FIFO without a writer may not receive the signal properly, causing the thread to hang indefinitely in do_exit(). The issue is addressed by ensuring the signal flag is set for bounded work started during io-wq exit, preventing loss of the signal and allowing proper termination.