Vulnerability Description
GNU coreutils unexpand is vulnerable to a heap-based buffer overflow due to an integer overflow during buffer allocation when processing large tab stop (-t) values. The multiplication used to calculate the allocation size can wrap around, resulting in an undersized buffer. When processing crafted input, subsequent writes exceed the allocated memory, leading to an out‑of‑bounds heap write. When running GNU coreutils unexpand with attacker-provided large tab stop (-t) arguments, this behavior leads to a crash and potentially achieve a heap write primitive depending on memory layout. This issue has been fixed in the commit b60a159fdc5bfcf9988d3a4cb6f53abe8ad5d35d
Related Weaknesses (CWE)
References
- https://cert.pl/en/posts/2026/07/CVE-2026-56391
- https://git.savannah.gnu.org/cgit/coreutils.git/
- https://git.savannah.gnu.org/cgit/coreutils.git/commit/?id=b60a159fdc5bfcf9988d3
FAQ
What is CVE-2026-56392?
CVE-2026-56392 is a documented vulnerability. GNU coreutils unexpand is vulnerable to a heap-based buffer overflow due to an integer overflow during buffer allocation when processing large tab stop (-t) values. The multiplication used to calculat...
How severe is CVE-2026-56392?
CVSS scoring is not yet available for CVE-2026-56392. Check NVD for updates.
Is there a patch for CVE-2026-56392?
Check the references section above for vendor advisories and patch information. Review vendor security bulletins for remediation guidance.