GNU coreutils integer overflow

Summaryinfo

A vulnerability was found in GNU coreutils. It has been rated as problematic. This affects an unknown part. This manipulation causes integer overflow. The identification of this vulnerability is CVE-2026-56392. The attack can only be executed locally. There is no exploit available.

Detailsinfo

A vulnerability classified as problematic was found in GNU coreutils (version unknown). Affected by this vulnerability is an unknown function. The manipulation with an unknown input leads to a integer overflow vulnerability. The CWE definition for the vulnerability is CWE-190. The product performs a calculation that can produce an integer overflow or wraparound, when the logic assumes that the resulting value will always be larger than the original value. This can introduce other weaknesses when the calculation is used for resource management or execution control. As an impact it is known to affect confidentiality, integrity, and availability. The summary by CVE is:

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

It is possible to read the advisory at cert.pl. This vulnerability is known as CVE-2026-56392 since 06/21/2026. The exploitation appears to be easy. Attacking locally is a requirement. It demands that the victim is doing some kind of user interaction. The technical details are unknown and an exploit is not publicly available.

Applying the patch b60a159fdc5bfcf9988d3a4cb6f53abe8ad5d35d is able to eliminate this problem.

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Productinfo

Vendor

• GNU

Name

• coreutils

License

• open-source

Website

• Vendor: https://www.gnu.org/

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