CVE-2026-56392
MediumCVSS 6.1Exploitation Probability (EPSS)
Low risk7th percentile - higher than 7% 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.
Other vulnerabilities in GNU coreutils
See all- CVE-2014-9471High
The parse_datetime function in GNU coreutils allows remote attackers to cause a denial of service (crash) or possibly execute arbitrary code via a crafted date string.
- CVE-2026-56391Medium
In the GNU coreutils uniq utility, an out-of-bounds read vulnerability exists due to incorrect handling of multibyte input when the -w (--check-chars) option is used. The find_field() function miscalculates byte length by repeatedly processing a fixed pointer instead of advancing through the input, resulting in an inflated length value. This incorrect length is later used in a memcmp operation, causing reads beyond the allocated buffer when processing crafted multibyte input, leading to a crash and potential adjacent heap memory exposure.
- CVE-2025-5278Medium
In GNU Coreutils, the begfield() function in the sort utility is vulnerable to a heap buffer under-read. A crafted command using the traditional key format may access memory outside the allocated buffer.
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
Vulnerability data from NVD (NIST) · CISA KEV · EPSS