CVE-2026-56391
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.
Leer descripción completaMostrar menos
This issue has been fixed in the commit d64e35a8a4c0e4608321433e0d84d917e4e36371.
CVSS
- Versión: 4.0
- Vector: 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
- Puntuación base: 4.6
Probabilidad de explotación (EPSS)
- Probabilidad de explotación en los próximos 30 días: 0.17%
- Percentil entre todas las CVEs puntuadas: 6
- Fecha de la puntuación: 5/10/2026
EPSS (Exploit Prediction Scoring System, de FIRST) estima la probabilidad de que una vulnerabilidad sea explotada en 30 días. Complementa a CVSS (impacto) y a CISA KEV (explotación confirmada).
Tecnologías afectadas (1)
CWE
- CWE-125
Referencias
JSON original (NVD)
Mostrar
{
"id": "CVE-2026-56391",
"cveTags": [],
"metrics": {
"ssvcV203": [
{
"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"ssvcData": {
"id": "CVE-2026-56391",
"role": "CISA Coordinator",
"options": [
{
"exploitation": "none"
},
{
"automatable": "no"
},
{
"technicalImpact": "partial"
}
],
"version": "2.0.3",
"timestamp": "2026-07-24T12:31:16.655541Z"
}
}
],
"cvssMetricV31": [
{
"type": "Primary",
"source": "nvd@nist.gov",
"cvssData": {
"scope": "UNCHANGED",
"version": "3.1",
"baseScore": 6.1,
"attackVector": "LOCAL",
"baseSeverity": "MEDIUM",
"vectorString": "CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:H",
"integrityImpact": "NONE",
"userInteraction": "REQUIRED",
"attackComplexity": "LOW",
"availabilityImpact": "HIGH",
"privilegesRequired": "NONE",
"confidentialityImpact": "LOW"
},
"impactScore": 4.2,
"exploitabilityScore": 1.8
}
],
"cvssMetricV40": [
{
"type": "Secondary",
"source": "cvd@cert.pl",
"cvssData": {
"Safety": "NOT_DEFINED",
"version": "4.0",
"Recovery": "NOT_DEFINED",
"baseScore": 4.6,
"Automatable": "NOT_DEFINED",
"attackVector": "LOCAL",
"baseSeverity": "MEDIUM",
"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",
"exploitMaturity": "NOT_DEFINED",
"providerUrgency": "NOT_DEFINED",
"userInteraction": "ACTIVE",
"attackComplexity": "LOW",
"attackRequirements": "NONE",
"privilegesRequired": "NONE",
"subIntegrityImpact": "NONE",
"vulnIntegrityImpact": "NONE",
"integrityRequirement": "NOT_DEFINED",
"modifiedAttackVector": "NOT_DEFINED",
"subAvailabilityImpact": "NONE",
"vulnAvailabilityImpact": "LOW",
"availabilityRequirement": "NOT_DEFINED",
"modifiedUserInteraction": "NOT_DEFINED",
"modifiedAttackComplexity": "NOT_DEFINED",
"subConfidentialityImpact": "NONE",
"vulnConfidentialityImpact": "LOW",
"confidentialityRequirement": "NOT_DEFINED",
"modifiedAttackRequirements": "NOT_DEFINED",
"modifiedPrivilegesRequired": "NOT_DEFINED",
"modifiedSubIntegrityImpact": "NOT_DEFINED",
"modifiedVulnIntegrityImpact": "NOT_DEFINED",
"vulnerabilityResponseEffort": "NOT_DEFINED",
"modifiedSubAvailabilityImpact": "NOT_DEFINED",
"modifiedVulnAvailabilityImpact": "NOT_DEFINED",
"modifiedSubConfidentialityImpact": "NOT_DEFINED",
"modifiedVulnConfidentialityImpact": "NOT_DEFINED"
}
}
]
},
"affected": [
{
"source": "cvd@cert.pl",
"affectedData": [
{
"vendor": "GNU",
"modules": [
"uniq"
],
"product": "coreutils",
"versions": [
{
"status": "affected",
"version": "9.5",
"versionType": "custom",
"lessThanOrEqual": "9.11"
}
],
"defaultStatus": "unaffected"
}
]
}
],
"published": "2026-07-24T09:16:25.003",
"references": [
{
"url": "https://cert.pl/en/posts/2026/07/CVE-2026-56391",
"tags": [
"Third Party Advisory"
],
"source": "cvd@cert.pl"
},
{
"url": "https://git.savannah.gnu.org/cgit/coreutils.git/",
"tags": [
"Product"
],
"source": "cvd@cert.pl"
},
{
"url": "https://git.savannah.gnu.org/cgit/coreutils.git/commit/?id=d64e35a8a4c0e4608321433e0d84d917e4e36371",
"tags": [
"Patch"
],
"source": "cvd@cert.pl"
}
],
"vulnStatus": "Analyzed",
"weaknesses": [
{
"type": "Secondary",
"source": "cvd@cert.pl",
"description": [
{
"lang": "en",
"value": "CWE-125"
}
]
}
],
"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."
}
],
"lastModified": "2026-08-26T13:52:50.660",
"configurations": [
{
"nodes": [
{
"negate": false,
"cpeMatch": [
{
"criteria": "cpe:2.3:a:gnu:coreutils:*:*:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "32AA16DF-2A52-4FEA-8A2D-94AEE9EEFD22",
"versionEndIncluding": "9.11",
"versionStartIncluding": "9.5"
}
],
"operator": "OR"
}
]
}
],
"sourceIdentifier": "cvd@cert.pl"
}