CVE-2026-56392
Severity CVSS v4.0:
LOW
Type:
CWE-122
Heap-based Buffer Overflow
Publication date:
24/07/2026
Last modified:
30/07/2026
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.<br />
When processing crafted input, subsequent writes exceed the allocated memory, leading to an out‑of‑bounds heap write.<br />
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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.<br />
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This issue has been fixed in the commit b60a159fdc5bfcf9988d3a4cb6f53abe8ad5d35d
Impact
Base Score 4.0
1.80
Severity 4.0
LOW