{
    "dataType": "CVE_RECORD",
    "dataVersion": "5.2",
    "cveMetadata": {
        "cveId": "CVE-2026-56391",
        "assignerOrgId": "4bb8329e-dd38-46c1-aafb-9bf32bcb93c6",
        "state": "PUBLISHED",
        "assignerShortName": "CERT-PL",
        "dateReserved": "2026-06-21T11:40:32.790Z",
        "datePublished": "2026-07-24T07:44:45.581Z",
        "dateUpdated": "2026-07-24T12:31:34.245Z"
    },
    "containers": {
        "cna": {
            "providerMetadata": {
                "orgId": "4bb8329e-dd38-46c1-aafb-9bf32bcb93c6",
                "shortName": "CERT-PL",
                "dateUpdated": "2026-07-24T07:44:45.581Z"
            },
            "title": "Out‑of‑bounds Read in GNU coreutils",
            "problemTypes": [
                {
                    "descriptions": [
                        {
                            "lang": "en",
                            "cweId": "CWE-125",
                            "description": "CWE-125 Out-of-bounds Read",
                            "type": "CWE"
                        }
                    ]
                }
            ],
            "affected": [
                {
                    "vendor": "GNU",
                    "product": "coreutils",
                    "modules": [
                        "uniq"
                    ],
                    "versions": [
                        {
                            "status": "affected",
                            "version": "9.5",
                            "lessThanOrEqual": "9.11",
                            "versionType": "custom"
                        }
                    ],
                    "defaultStatus": "unaffected"
                }
            ],
            "descriptions": [
                {
                    "lang": "en",
                    "value": "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.",
                    "supportingMedia": [
                        {
                            "type": "text/html",
                            "base64": false,
                            "value": "GNU coreutils <i>uniq</i> is vulnerable to an out‑of‑bounds read due to incorrect handling of multibyte input when the <i>-w (--check-chars)</i> option is used. The <i>find_field()</i> 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. <br>This incorrect length is later used in a memcmp operation, causing reads beyond the allocated buffer when processing crafted multibyte input.<br><br>When running GNU coreutils <i>uniq</i> with attacker-provided arguments, this behavior leads to a crash and potential adjacent heap memory exposure.<br><p>This issue has been fixed in the commit d64e35a8a4c0e4608321433e0d84d917e4e36371.</p>"
                        }
                    ]
                }
            ],
            "tags": [
                "x_open-source"
            ],
            "references": [
                {
                    "url": "https://cert.pl/en/posts/2026/07/CVE-2026-56391",
                    "tags": [
                        "third-party-advisory"
                    ]
                },
                {
                    "url": "https://git.savannah.gnu.org/cgit/coreutils.git/",
                    "tags": [
                        "product"
                    ]
                },
                {
                    "url": "https://git.savannah.gnu.org/cgit/coreutils.git/commit/?id=d64e35a8a4c0e4608321433e0d84d917e4e36371",
                    "tags": [
                        "patch"
                    ]
                }
            ],
            "metrics": [
                {
                    "format": "CVSS",
                    "scenarios": [
                        {
                            "lang": "en",
                            "value": "GENERAL"
                        }
                    ],
                    "cvssV4_0": {
                        "attackVector": "LOCAL",
                        "attackComplexity": "LOW",
                        "attackRequirements": "NONE",
                        "privilegesRequired": "NONE",
                        "userInteraction": "ACTIVE",
                        "vulnConfidentialityImpact": "LOW",
                        "subConfidentialityImpact": "NONE",
                        "vulnIntegrityImpact": "NONE",
                        "subIntegrityImpact": "NONE",
                        "vulnAvailabilityImpact": "LOW",
                        "subAvailabilityImpact": "NONE",
                        "exploitMaturity": "NOT_DEFINED",
                        "Safety": "NOT_DEFINED",
                        "Automatable": "NOT_DEFINED",
                        "Recovery": "NOT_DEFINED",
                        "valueDensity": "NOT_DEFINED",
                        "vulnerabilityResponseEffort": "NOT_DEFINED",
                        "providerUrgency": "NOT_DEFINED",
                        "version": "4.0",
                        "baseSeverity": "MEDIUM",
                        "baseScore": 4.6,
                        "vectorString": "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"
                    }
                }
            ],
            "credits": [
                {
                    "lang": "en",
                    "value": "Michał Majchrowicz (AFINE Team)",
                    "type": "finder"
                },
                {
                    "lang": "en",
                    "value": "Marcin Wyczechowski (AFINE Team)",
                    "type": "finder"
                }
            ],
            "source": {
                "discovery": "EXTERNAL"
            },
            "x_generator": {
                "engine": "Vulnogram 0.2.0"
            }
        },
        "adp": [
            {
                "metrics": [
                    {
                        "other": {
                            "type": "ssvc",
                            "content": {
                                "timestamp": "2026-07-24T12:31:16.655541Z",
                                "id": "CVE-2026-56391",
                                "options": [
                                    {
                                        "Exploitation": "none"
                                    },
                                    {
                                        "Automatable": "no"
                                    },
                                    {
                                        "Technical Impact": "partial"
                                    }
                                ],
                                "role": "CISA Coordinator",
                                "version": "2.0.3"
                            }
                        }
                    }
                ],
                "title": "CISA ADP Vulnrichment",
                "providerMetadata": {
                    "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
                    "shortName": "CISA-ADP",
                    "dateUpdated": "2026-07-24T12:31:34.245Z"
                }
            }
        ]
    }
}