{
  "affected": [
    {
      "ranges": [
        {
          "database_specific": {
            "source": "REFERENCES"
          },
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "d64e35a8a4c0e4608321433e0d84d917e4e36371"
            }
          ],
          "repo": "https://cgit.git.savannah.gnu.org/cgit/coreutils.git",
          "type": "GIT"
        },
        {
          "database_specific": {
            "cpe": "cpe:2.3:a:gnu:coreutils:*:*:*:*:*:*:*:*",
            "extracted_events": [
              {
                "introduced": "9.5"
              },
              {
                "last_affected": "9.11"
              }
            ],
            "source": "CPE_RANGE"
          },
          "events": [
            {
              "introduced": "cc8689a07c8cfece66707936e3b914174912bd36"
            },
            {
              "last_affected": "c01fd163a47468a8296fb369f5233853bb551bb6"
            }
          ],
          "repo": "https://github.com/coreutils/coreutils",
          "type": "GIT"
        },
        {
          "database_specific": {
            "extracted_events": [
              {
                "introduced": "9.5"
              },
              {
                "last_affected": "9.11"
              }
            ],
            "source": "AFFECTED_FIELD"
          },
          "events": [
            {
              "introduced": "cc8689a07c8cfece66707936e3b914174912bd36"
            },
            {
              "last_affected": "c01fd163a47468a8296fb369f5233853bb551bb6"
            }
          ],
          "repo": "https://https.git.savannah.gnu.org/git/coreutils.git/",
          "type": "GIT"
        }
      ]
    }
  ],
  "database_specific": {
    "cna_assigner": "CERT-PL",
    "cwe_ids": [
      "CWE-125"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/56xxx/CVE-2026-56391.json"
  },
  "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. \nThis incorrect length is later used in a memcmp operation, causing reads beyond the allocated buffer when processing crafted multibyte input.\n\nWhen running GNU coreutils uniq with attacker-provided arguments, this behavior leads to a crash and potential adjacent heap memory exposure.\n\n\nThis issue has been fixed in the commit d64e35a8a4c0e4608321433e0d84d917e4e36371.",
  "id": "CVE-2026-56391",
  "modified": "2026-09-03T11:30:38.245375953Z",
  "published": "2026-07-24T07:44:45.581Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://git.savannah.gnu.org/cgit/coreutils.git/"
    },
    {
      "type": "ADVISORY",
      "url": "https://cert.pl/en/posts/2026/07/CVE-2026-56391"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/56xxx/CVE-2026-56391.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-56391"
    },
    {
      "type": "FIX",
      "url": "https://git.savannah.gnu.org/cgit/coreutils.git/commit/?id=d64e35a8a4c0e4608321433e0d84d917e4e36371"
    }
  ],
  "schema_version": "1.9.0",
  "severity": [
    {
      "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_V4"
    }
  ],
  "summary": "Out‑of‑bounds Read in GNU coreutils"
}