{"id":"UBUNTU-CVE-2026-56391","details":"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.","modified":"2026-08-31T17:16:16.205785347Z","published":"2026-07-24T09:16:00Z","related":["USN-8697-1"],"upstream":["CVE-2026-56391"],"references":[{"type":"REPORT","url":"https://ubuntu.com/security/CVE-2026-56391"},{"type":"REPORT","url":"https://www.cve.org/CVERecord?id=CVE-2026-56391"},{"type":"REPORT","url":"https://www.openwall.com/lists/oss-security/2026/07/25/2"},{"type":"REPORT","url":"https://cert.pl/en/posts/2026/07/CVE-2026-56391"},{"type":"ADVISORY","url":"https://ubuntu.com/security/notices/USN-8697-1"}],"affected":[{"package":{"name":"coreutils","ecosystem":"Ubuntu:26.04:LTS","purl":"pkg:deb/ubuntu/coreutils?arch=source&distro=resolute"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"9.7-3ubuntu2.1"}]}],"versions":["9.5-1ubuntu4","9.7-3ubuntu1","9.7-3ubuntu2"],"ecosystem_specific":{"binaries":[{"binary_name":"gnu-coreutils","binary_version":"9.7-3ubuntu2.1"}],"availability":"No subscription required"},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-56391.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V4","score":"CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:L/VI:N/VA:L/SC:N/SI:N/SA:N"},{"type":"CVSS_V3","score":"CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:H"},{"type":"Ubuntu","score":"medium"}]}