Heap-Based Buffer Overflow in GNU Coreutils Unexpand Affects Multiple Users

CVE-2026-56392

What is CVE-2026-56392?

The GNU coreutils 'unexpand' command is susceptible to a heap-based buffer overflow due to integer overflow during memory allocation when handling large tab stop (-t) values. This flaw arises from the calculation used to determine the allocation size, which may lead to an undersized buffer when processing crafted input. An attacker providing excessively large arguments can exploit this vulnerability, resulting in an out-of-bounds write that might crash the application or allow for further exploitations based on the memory layout. A patch has been implemented to address this issue.

References