CVE-2026-12064
When a user invokes curl using a schemeless URL combined with `--proto-default` sftp (or scp), a disconnect occurs between the tool layer and libcurl. The tool layer incorrectly infers the URL scheme, which erroneously bypasses the initialization of critical SSH security options like CURLOPT_SSH_HOST_PUBLIC_KEY_SHA256 and CURLOPT_SSH_KNOWNHOSTS. Conversely, the libcurl runtime successfully honors CURLOPT_DEFAULT_PROTOCOL and establishes the connection via SFTP/SCP as specified. Because the tool layer skipped the security configuration, these SSH host verification options are silently omitted, causing curl to connect to an unverified SSH remote host without throwing an error.
CVSS
- Versión: 3.1
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
- Puntuación base: 7.5
Probabilidad de explotación (EPSS)
- Probabilidad de explotación en los próximos 30 días: 0.40%
- Percentil entre todas las CVEs puntuadas: 32
- Fecha de la puntuación: 6/10/2026
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).
🎯 Técnicas ATT&CK
Cómo se explota esta vulnerabilidad y qué consigue el atacante, en el lenguaje de MITRE ATT&CK.
- Explotación
T1557Adversary-in-the-Middlecredential access · collection75 % - Impacto principal
T1041Exfiltration Over C2 Channelexfiltration70 %
Bypass de verificación SSH (CWE-297, CWE-295) en curl permite interceptación de tráfico (man-in-the-middle) y exfiltración de datos sin autenticación de host remoto (AV:N, PR:N, UI:N).
Inferido por nuestro agente de análisis a partir de la descripción oficial, el vector CVSS y la CWE, y comprobado por un supervisor. Puede contener errores.
🛡️ Mitigaciones ATT&CK que cubren estas técnicas
Tecnologías afectadas (1)
CWE
- CWE-297
- CWE-295
Referencias
JSON original (NVD)
Mostrar
{
"id": "CVE-2026-12064",
"cveTags": [],
"metrics": {
"ssvcV203": [
{
"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"ssvcData": {
"id": "CVE-2026-12064",
"role": "CISA Coordinator",
"options": [
{
"exploitation": "poc"
},
{
"automatable": "yes"
},
{
"technicalImpact": "partial"
}
],
"version": "2.0.3",
"timestamp": "2026-07-06T18:19:34.951461Z"
}
}
],
"cvssMetricV31": [
{
"type": "Secondary",
"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"cvssData": {
"scope": "UNCHANGED",
"version": "3.1",
"baseScore": 7.5,
"attackVector": "NETWORK",
"baseSeverity": "HIGH",
"vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N",
"integrityImpact": "HIGH",
"userInteraction": "NONE",
"attackComplexity": "LOW",
"availabilityImpact": "NONE",
"privilegesRequired": "NONE",
"confidentialityImpact": "NONE"
},
"impactScore": 3.6,
"exploitabilityScore": 3.9
}
]
},
"affected": [
{
"source": "2499f714-1537-4658-8207-48ae4bb9eae9",
"affectedData": [
{
"vendor": "curl",
"product": "curl",
"versions": [
{
"status": "affected",
"version": "7.81.0",
"lessThan": "8.14.2",
"versionType": "semver"
},
{
"status": "affected",
"version": "8.15.0",
"lessThan": "8.16.1",
"versionType": "semver"
},
{
"status": "affected",
"version": "8.17.0",
"lessThan": "8.20.1",
"versionType": "semver"
}
],
"defaultStatus": "unaffected"
},
{
"repo": "https://github.com/curl/curl.git",
"vendor": "curl",
"product": "curl",
"versions": [
{
"status": "affected",
"version": "18270893abdb19f0ca170c118f8a2847dbd304be",
"lessThan": "ab3bb8cd8be8f9d4acb97da0418abc279182041e",
"versionType": "git"
}
],
"defaultStatus": "unaffected"
},
{
"vendor": "curl",
"product": "curl",
"versions": [
{
"status": "affected",
"version": "8.20.0"
},
{
"status": "affected",
"version": "8.19.0"
},
{
"status": "affected",
"version": "8.18.0"
},
{
"status": "affected",
"version": "8.17.0"
},
{
"status": "affected",
"version": "8.16.0"
},
{
"status": "affected",
"version": "8.15.0"
},
{
"status": "affected",
"version": "8.14.1"
},
{
"status": "affected",
"version": "8.14.0"
},
{
"status": "affected",
"version": "8.13.0"
},
{
"status": "affected",
"version": "8.12.1"
},
{
"status": "affected",
"version": "8.12.0"
},
{
"status": "affected",
"version": "8.11.1"
},
{
"status": "affected",
"version": "8.11.0"
},
{
"status": "affected",
"version": "8.10.1"
},
{
"status": "affected",
"version": "8.10.0"
},
{
"status": "affected",
"version": "8.9.1"
},
{
"status": "affected",
"version": "8.9.0"
},
{
"status": "affected",
"version": "8.8.0"
},
{
"status": "affected",
"version": "8.7.1"
},
{
"status": "affected",
"version": "8.7.0"
},
{
"status": "affected",
"version": "8.6.0"
},
{
"status": "affected",
"version": "8.5.0"
},
{
"status": "affected",
"version": "8.4.0"
},
{
"status": "affected",
"version": "8.3.0"
},
{
"status": "affected",
"version": "8.2.1"
},
{
"status": "affected",
"version": "8.2.0"
},
{
"status": "affected",
"version": "8.1.2"
},
{
"status": "affected",
"version": "8.1.1"
},
{
"status": "affected",
"version": "8.1.0"
},
{
"status": "affected",
"version": "8.0.1"
},
{
"status": "affected",
"version": "8.0.0"
},
{
"status": "affected",
"version": "7.88.1"
},
{
"status": "affected",
"version": "7.88.0"
},
{
"status": "affected",
"version": "7.87.0"
},
{
"status": "affected",
"version": "7.86.0"
},
{
"status": "affected",
"version": "7.85.0"
},
{
"status": "affected",
"version": "7.84.0"
},
{
"status": "affected",
"version": "7.83.1"
},
{
"status": "affected",
"version": "7.83.0"
},
{
"status": "affected",
"version": "7.82.0"
},
{
"status": "affected",
"version": "7.81.0"
}
],
"defaultStatus": "unaffected"
}
]
}
],
"published": "2026-07-03T07:16:24.217",
"references": [
{
"url": "https://curl.se/docs/CVE-2026-12064.html",
"tags": [
"Patch",
"Vendor Advisory"
],
"source": "2499f714-1537-4658-8207-48ae4bb9eae9"
},
{
"url": "https://curl.se/docs/CVE-2026-12064.json",
"tags": [
"Vendor Advisory"
],
"source": "2499f714-1537-4658-8207-48ae4bb9eae9"
},
{
"url": "https://hackerone.com/reports/3797526",
"tags": [
"Exploit",
"Issue Tracking",
"Third Party Advisory"
],
"source": "2499f714-1537-4658-8207-48ae4bb9eae9"
},
{
"url": "https://hackerone.com/reports/3797526",
"tags": [
"Exploit",
"Issue Tracking",
"Third Party Advisory"
],
"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0"
}
],
"vulnStatus": "Modified",
"weaknesses": [
{
"type": "Secondary",
"source": "2499f714-1537-4658-8207-48ae4bb9eae9",
"description": [
{
"lang": "en",
"value": "CWE-297"
}
]
},
{
"type": "Primary",
"source": "nvd@nist.gov",
"description": [
{
"lang": "en",
"value": "CWE-295"
}
]
}
],
"descriptions": [
{
"lang": "en",
"value": "When a user invokes curl using a schemeless URL combined with\n`--proto-default` sftp (or scp), a disconnect occurs between the tool layer\nand libcurl. The tool layer incorrectly infers the URL scheme, which\nerroneously bypasses the initialization of critical SSH security options like\nCURLOPT_SSH_HOST_PUBLIC_KEY_SHA256 and CURLOPT_SSH_KNOWNHOSTS. Conversely, the\nlibcurl runtime successfully honors CURLOPT_DEFAULT_PROTOCOL and establishes\nthe connection via SFTP/SCP as specified. Because the tool layer skipped the\nsecurity configuration, these SSH host verification options are silently\nomitted, causing curl to connect to an unverified SSH remote host without\nthrowing an error."
}
],
"lastModified": "2026-09-15T07:16:26.150",
"configurations": [
{
"nodes": [
{
"negate": false,
"cpeMatch": [
{
"criteria": "cpe:2.3:a:haxx:curl:*:*:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "53E9B785-AB1F-48AC-B737-EEB59C80E5BF",
"versionEndExcluding": "8.21.0",
"versionStartIncluding": "7.81.0"
}
],
"operator": "OR"
}
]
}
],
"sourceIdentifier": "2499f714-1537-4658-8207-48ae4bb9eae9"
}