CVE-2026-56289
Full vulnerability record from the local CVENow database.
Description
GNU patch is vulnerable to a denial of service (DoS) due to improper validation of hunk (single block of changes in diff) line offsets in unified-diff input. A specially crafted patch can specify an extremely large line number, causing the application to enter an effectively infinite processing loop while attempting to locate the requested position. This results in excessive CPU consumption and prevents the process from completing. An attacker can trigger this behavior by supplying a malicious patch file, causing the utility to become unresponsive and require manual termination. This issue has been fixed in the commit faba04ef4f2b410257f76c1b9dc85e350929c4b9
Severity
MEDIUM
CVSS score
4.6
(v4.0)
Vulnerability status
Analyzed
Source identifier
Published
2026-07-09 11:16:40.840000
Last modified
2026-10-25 17:10:00.197000
View original CVE JSON
{
"id": "CVE-2026-56289",
"sourceIdentifier": "[email protected]",
"published": "2026-07-09T11:16:40.840",
"lastModified": "2026-10-25T17:10:00.197",
"vulnStatus": "Analyzed",
"cveTags": [],
"descriptions": [
{
"lang": "en",
"value": "GNU patch is vulnerable to a denial of service (DoS) due to improper validation of hunk (single block of changes in diff) line offsets in unified-diff input. A specially crafted patch can specify an extremely large line number, causing the application to enter an effectively infinite processing loop while attempting to locate the requested position.\nThis results in excessive CPU consumption and prevents the process from completing.\nAn attacker can trigger this behavior by supplying a malicious patch file, causing the utility to become unresponsive and require manual termination.\n\n\n\nThis issue has been fixed in the commit faba04ef4f2b410257f76c1b9dc85e350929c4b9"
},
{
"lang": "es",
"value": "GNU patch es vulnerable a una denegación de servicio (DoS) debido a una validación incorrecta de los desplazamientos de línea de los hunks (bloque único de cambios en un diff) en la entrada unified-diff. Un parche especialmente diseñado puede especificar un número de línea extremadamente grande, lo que hace que la aplicación entre en un bucle de procesamiento efectivamente infinito mientras intenta localizar la posición solicitada. Esto resulta en un consumo excesivo de CPU y evita que el proceso se complete. Un atacante puede desencadenar este comportamiento al proporcionar un archivo de parche malicioso, lo que hace que la utilidad deje de responder y requiera una terminación manual.\n\nEste problema ha sido solucionado en el commit faba04ef4f2b410257f76c1b9dc85e350929c4b9"
}
],
"affected": [
{
"source": "[email protected]",
"affectedData": [
{
"vendor": "GNU",
"product": "patch",
"defaultStatus": "unaffected",
"repo": "https://cgit.git.savannah.gnu.org/cgit/patch.git/",
"versions": [
{
"version": "0",
"lessThanOrEqual": "2.8.0",
"versionType": "semver",
"status": "affected"
}
]
}
]
}
],
"metrics": {
"cvssMetricV40": [
{
"source": "[email protected]",
"type": "Secondary",
"cvssData": {
"version": "4.0",
"vectorString": "CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:L/SC:N/SI:N/SA:L/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",
"baseScore": 4.6,
"baseSeverity": "MEDIUM",
"attackVector": "LOCAL",
"attackComplexity": "LOW",
"attackRequirements": "NONE",
"privilegesRequired": "NONE",
"userInteraction": "ACTIVE",
"vulnConfidentialityImpact": "NONE",
"vulnIntegrityImpact": "NONE",
"vulnAvailabilityImpact": "LOW",
"subConfidentialityImpact": "NONE",
"subIntegrityImpact": "NONE",
"subAvailabilityImpact": "LOW",
"exploitMaturity": "NOT_DEFINED",
"confidentialityRequirement": "NOT_DEFINED",
"integrityRequirement": "NOT_DEFINED",
"availabilityRequirement": "NOT_DEFINED",
"modifiedAttackVector": "NOT_DEFINED",
"modifiedAttackComplexity": "NOT_DEFINED",
"modifiedAttackRequirements": "NOT_DEFINED",
"modifiedPrivilegesRequired": "NOT_DEFINED",
"modifiedUserInteraction": "NOT_DEFINED",
"modifiedVulnConfidentialityImpact": "NOT_DEFINED",
"modifiedVulnIntegrityImpact": "NOT_DEFINED",
"modifiedVulnAvailabilityImpact": "NOT_DEFINED",
"modifiedSubConfidentialityImpact": "NOT_DEFINED",
"modifiedSubIntegrityImpact": "NOT_DEFINED",
"modifiedSubAvailabilityImpact": "NOT_DEFINED",
"Safety": "NOT_DEFINED",
"Automatable": "NOT_DEFINED",
"Recovery": "NOT_DEFINED",
"valueDensity": "NOT_DEFINED",
"vulnerabilityResponseEffort": "NOT_DEFINED",
"providerUrgency": "NOT_DEFINED"
}
}
],
"cvssMetricV31": [
{
"source": "[email protected]",
"type": "Primary",
"cvssData": {
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"vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
"baseScore": 5.5,
"baseSeverity": "MEDIUM",
"attackVector": "LOCAL",
"attackComplexity": "LOW",
"privilegesRequired": "LOW",
"userInteraction": "NONE",
"scope": "UNCHANGED",
"confidentialityImpact": "NONE",
"integrityImpact": "NONE",
"availabilityImpact": "HIGH"
},
"exploitabilityScore": 1.8,
"impactScore": 3.6
}
],
"ssvcV203": [
{
"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"ssvcData": {
"timestamp": "2026-07-09T12:20:43.274659Z",
"id": "CVE-2026-56289",
"options": [
{
"exploitation": "none"
},
{
"automatable": "no"
},
{
"technicalImpact": "partial"
}
],
"role": "CISA Coordinator",
"version": "2.0.3"
}
}
]
},
"weaknesses": [
{
"source": "[email protected]",
"type": "Secondary",
"description": [
{
"lang": "en",
"value": "CWE-835"
}
]
}
],
"configurations": [
{
"nodes": [
{
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"negate": false,
"cpeMatch": [
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"references": [
{
"url": "https://cert.pl/en/posts/2026/07/CVE-2026-56288",
"source": "[email protected]",
"tags": [
"Third Party Advisory"
]
},
{
"url": "https://cgit.git.savannah.gnu.org/cgit/patch.git/",
"source": "[email protected]",
"tags": [
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},
{
"url": "https://cgit.git.savannah.gnu.org/cgit/patch.git/commit/?id=faba04ef4f2b410257f76c1b9dc85e350929c4b9",
"source": "[email protected]",
"tags": [
"Patch"
]
}
]
}