Quick answers
- Is CVE-2026-56392 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-56392 being exploited in the wild.
- How severe is CVE-2026-56392?
- Informational severity, with a CVSS score of 1.8, published 24 July 2026.
- Which products and versions are affected?
- Gnu Coreutils All through 9.11.
- Is there a fix for CVE-2026-56392?
- No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.
- How is CVE-2026-56392 attacked?
- It is attacked with local access, in an operating system.
- Am I affected by CVE-2026-56392?
- Check whether you run Gnu Coreutils at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.
Technical details
A heap-based buffer overflow exists in the GNU coreutils 'unexpand' utility. The vulnerability is caused by an integer overflow during memory allocation when the program processes large tab stop values provided via the '-t' command-line argument. Specifically, a multiplication operation used to calculate the required buffer size can wrap around, resulting in an undersized heap allocation. Subsequent write operations then exceed the buffer boundaries. An attacker who can control the arguments passed to 'unexpand' can trigger a crash or potentially achieve a heap write primitive. The issue has been addressed in commit b60a159fdc5bfcf9988d3a4cb6f53abe8ad5d35d.
Affected products
- GNU coreutils All through 9.11
Timeline
- 2026-07-24: disclosed
- 2026-07-24: advisory