Threats Tagged 'cve-2026-56391'

Red Hat has issued a security advisory addressing vulnerabilities in the GNU coreutils package, specifically affecting the uniq and unexpand utilities. The uniq utility suffers from a denial of service and information disclosure vulnerability due to an out-of-bounds read with multibyte input (CVE-2026-56391). The unexpand utility is vulnerable to denial of service through crafted tab stop values (CVE-2026-56392). Updated coreutils packages have been released to mitigate these issues.

GNU coreutils uniq is vulnerable to an out‑of‑bounds read due to incorrect handling of multibyte input when the -w (--check-chars) option is used. The find_field() function miscalculates the byte length of characters 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. When running GNU coreutils uniq with attacker-provided arguments, this behavior leads to a crash and potential adjacent heap memory exposure. This issue has been fixed in the commit d64e35a8a4c0e4608321433e0d84d917e4e36371.