FKIE_CVE-2026-56391
Vulnerability from fkie_nvd - Published: 2026-07-24 09:16 - Updated: 2026-10-24 13:10
Severity
Summary
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.
References
{
"affected": [
{
"affectedData": [
{
"defaultStatus": "unaffected",
"modules": [
"uniq"
],
"product": "coreutils",
"vendor": "GNU",
"versions": [
{
"lessThanOrEqual": "9.11",
"status": "affected",
"version": "9.5",
"versionType": "custom"
}
]
}
],
"source": "cvd@cert.pl"
}
],
"configurations": [
{
"nodes": [
{
"cpeMatch": [
{
"criteria": "cpe:2.3:a:gnu:coreutils:*:*:*:*:*:*:*:*",
"matchCriteriaId": "32AA16DF-2A52-4FEA-8A2D-94AEE9EEFD22",
"versionEndIncluding": "9.11",
"versionStartIncluding": "9.5",
"vulnerable": true
}
],
"negate": false,
"operator": "OR"
}
]
}
],
"cveTags": [],
"descriptions": [
{
"lang": "en",
"value": "GNU coreutils uniq is vulnerable to an out\u2011of\u2011bounds 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."
},
{
"lang": "es",
"value": "GNU coreutils uniq es vulnerable a una lectura fuera de l\u00edmites debido a un manejo incorrecto de entrada multibyte cuando se utiliza la opci\u00f3n -w (--check-chars). La funci\u00f3n find_field() calcula incorrectamente la longitud en bytes de los caracteres al procesar repetidamente un puntero fijo en lugar de avanzar a trav\u00e9s de la entrada, lo que resulta en un valor de longitud inflado.\nEsta longitud incorrecta se utiliza posteriormente en una operaci\u00f3n memcmp, causando lecturas m\u00e1s all\u00e1 del b\u00fafer asignado al procesar entrada multibyte manipulada.\n\nAl ejecutar GNU coreutils uniq con argumentos proporcionados por el atacante, este comportamiento conduce a un fallo y a una posible exposici\u00f3n de memoria adyacente del heap.\n\nEste problema ha sido corregido en el commit d64e35a8a4c0e4608321433e0d84d917e4e36371."
}
],
"id": "CVE-2026-56391",
"lastModified": "2026-10-24T13:10:00.147",
"metrics": {
"cvssMetricV31": [
{
"cvssData": {
"attackComplexity": "LOW",
"attackVector": "LOCAL",
"availabilityImpact": "HIGH",
"baseScore": 6.1,
"baseSeverity": "MEDIUM",
"confidentialityImpact": "LOW",
"integrityImpact": "NONE",
"privilegesRequired": "NONE",
"scope": "UNCHANGED",
"userInteraction": "REQUIRED",
"vectorString": "CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:H",
"version": "3.1"
},
"exploitabilityScore": 1.8,
"impactScore": 4.2,
"source": "nvd@nist.gov",
"type": "Primary"
}
],
"cvssMetricV40": [
{
"cvssData": {
"Automatable": "NOT_DEFINED",
"Recovery": "NOT_DEFINED",
"Safety": "NOT_DEFINED",
"attackComplexity": "LOW",
"attackRequirements": "NONE",
"attackVector": "LOCAL",
"availabilityRequirement": "NOT_DEFINED",
"baseScore": 4.6,
"baseSeverity": "MEDIUM",
"confidentialityRequirement": "NOT_DEFINED",
"exploitMaturity": "NOT_DEFINED",
"integrityRequirement": "NOT_DEFINED",
"modifiedAttackComplexity": "NOT_DEFINED",
"modifiedAttackRequirements": "NOT_DEFINED",
"modifiedAttackVector": "NOT_DEFINED",
"modifiedPrivilegesRequired": "NOT_DEFINED",
"modifiedSubAvailabilityImpact": "NOT_DEFINED",
"modifiedSubConfidentialityImpact": "NOT_DEFINED",
"modifiedSubIntegrityImpact": "NOT_DEFINED",
"modifiedUserInteraction": "NOT_DEFINED",
"modifiedVulnAvailabilityImpact": "NOT_DEFINED",
"modifiedVulnConfidentialityImpact": "NOT_DEFINED",
"modifiedVulnIntegrityImpact": "NOT_DEFINED",
"privilegesRequired": "NONE",
"providerUrgency": "NOT_DEFINED",
"subAvailabilityImpact": "NONE",
"subConfidentialityImpact": "NONE",
"subIntegrityImpact": "NONE",
"userInteraction": "ACTIVE",
"valueDensity": "NOT_DEFINED",
"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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X",
"version": "4.0",
"vulnAvailabilityImpact": "LOW",
"vulnConfidentialityImpact": "LOW",
"vulnIntegrityImpact": "NONE",
"vulnerabilityResponseEffort": "NOT_DEFINED"
},
"source": "cvd@cert.pl",
"type": "Secondary"
}
],
"ssvcV203": [
{
"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"ssvcData": {
"id": "CVE-2026-56391",
"options": [
{
"exploitation": "none"
},
{
"automatable": "no"
},
{
"technicalImpact": "partial"
}
],
"role": "CISA Coordinator",
"timestamp": "2026-07-24T12:31:16.655541Z",
"version": "2.0.3"
}
}
]
},
"published": "2026-07-24T09:16:25.003",
"references": [
{
"source": "cvd@cert.pl",
"tags": [
"Third Party Advisory"
],
"url": "https://cert.pl/en/posts/2026/07/CVE-2026-56391"
},
{
"source": "cvd@cert.pl",
"tags": [
"Product"
],
"url": "https://git.savannah.gnu.org/cgit/coreutils.git/"
},
{
"source": "cvd@cert.pl",
"tags": [
"Patch"
],
"url": "https://git.savannah.gnu.org/cgit/coreutils.git/commit/?id=d64e35a8a4c0e4608321433e0d84d917e4e36371"
}
],
"sourceIdentifier": "cvd@cert.pl",
"vulnStatus": "Analyzed",
"weaknesses": [
{
"description": [
{
"lang": "en",
"value": "CWE-125"
}
],
"source": "cvd@cert.pl",
"type": "Secondary"
}
]
}
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Browse all ATT&CK techniques and the vulnerabilities related to each.
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