CVE-2026-56392
LowCVSS 1.8Exploitation Probability (EPSS)
Low risk5th percentile - higher than 5% of all known CVEs
Summary
In GNU coreutils unexpand, a heap-based buffer overflow occurs due to an integer overflow during buffer allocation when processing large -t values. This can lead to out-of-bounds heap write and potentially achieve a heap write primitive.
Risk Assessment
An attacker can cause a program crash or potentially achieve code execution depending on memory layout, posing a serious threat to systems processing user-supplied input.
Recommendation
Apply the patch available in commit b60a159fdc5bfcf9988d3a4cb6f53abe8ad5d35d or update coreutils to a version containing the fix.
Original NVD description (English source)
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