glibc, the GNU C Library, is the standard C library used by most Linux systems. It supplies basic functions for memory handling, string processing, networking, file access, and process control, so countless programs depend on it at runtime. Because it sits so close to the base of the operating system, a flaw in glibc can affect many applications at once rather than only one package.
In cyber security, that makes glibc a high-value target and a high-priority patch item. Attackers may try to exploit memory-safety or input-handling bugs to crash a process or achieve arbitrary code execution, especially when the vulnerable code is reached through untrusted data. Defenders watch for glibc updates, test core-library changes carefully, and reduce exposure with least privilege, sandboxing, and rapid patching on systems that handle external input.