CVE-2026-68457
In the Linux kernel, the following vulnerability has been resolved:
ksmbd: use opener credentials for FSCTL mutations
SET_SPARSE, SET_ZERO_DATA and SET_COMPRESSION operate on an open SMB handle but call VFS xattr, fallocate or fileattr helpers with the current ksmbd worker credentials. Those helpers can revalidate inode permissions, ownership and LSM policy independently of the SMB handle access mask.
Run each operation with the credentials captured in the target file when the handle was opened. Keep credential handling local to these single-file FSCTLs rather than applying session credentials to the complete IOCTL handler, which also contains handle-less and multi-handle operations.
CVSS
- Versión: 3.1
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H
- Puntuación base: 9.1
Probabilidad de explotación (EPSS)
- Probabilidad de explotación en los próximos 30 días: 0.70%
- Percentil entre todas las CVEs puntuadas: 52
- 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
T1190Exploit Public-Facing Applicationinitial access75 % - Impacto principal
T1565.001Stored Data Manipulationimpact70 %
Vector CVSS:N sin privilegios ni interacción sugiere T1190. La vulnerabilidad permite mutar atributos de fichero (SET_SPARSE, SET_ZERO_DATA) con credenciales del worker, causando corrupción de datos (I:H) y potencial DoS (A:H).
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)
⚠ Inferidas por IA a partir de la descripción — NVD aún no ha analizado esta CVE; no son CPE verificados.
Referencias
- https://git.kernel.org/stable/c/1e112c47ec5dd1942e2d4ca6e8e9b712238e20c2
- https://git.kernel.org/stable/c/a8c18434e1f0d9f7989170bdb0490c0160baf065
- https://git.kernel.org/stable/c/c6394bcaf254c5baf9aff43376020be5db6d3316
- https://git.kernel.org/stable/c/cfb2c6f71d61ed807c9d7a7af331d406f1f31877
- https://git.kernel.org/stable/c/e205f3e7e8c31a47cd11efb6cf663a527177e432
- https://git.kernel.org/stable/c/fb1cae6302d58414ddf029e3f642711bd30243f7
JSON original (NVD)
Mostrar
{
"id": "CVE-2026-68457",
"cveTags": [],
"metrics": {
"cvssMetricV31": [
{
"type": "Secondary",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"cvssData": {
"scope": "UNCHANGED",
"version": "3.1",
"baseScore": 9.1,
"attackVector": "NETWORK",
"baseSeverity": "CRITICAL",
"vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H",
"integrityImpact": "HIGH",
"userInteraction": "NONE",
"attackComplexity": "LOW",
"availabilityImpact": "HIGH",
"privilegesRequired": "NONE",
"confidentialityImpact": "NONE"
},
"impactScore": 5.2,
"exploitabilityScore": 3.9
}
]
},
"affected": [
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"affectedData": [
{
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],
"programFiles": [
"fs/smb/server/smb2pdu.c",
"fs/smb/server/vfs.c"
],
"defaultStatus": "unaffected"
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "5.15"
},
{
"status": "unaffected",
"version": "0",
"lessThan": "5.15",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "6.1.178",
"versionType": "semver",
"lessThanOrEqual": "6.1.*"
},
{
"status": "unaffected",
"version": "6.6.145",
"versionType": "semver",
"lessThanOrEqual": "6.6.*"
},
{
"status": "unaffected",
"version": "6.12.97",
"versionType": "semver",
"lessThanOrEqual": "6.12.*"
},
{
"status": "unaffected",
"version": "6.18.40",
"versionType": "semver",
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},
{
"status": "unaffected",
"version": "7.1.5",
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},
{
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"version": "7.2",
"versionType": "original_commit_for_fix",
"lessThanOrEqual": "*"
}
],
"programFiles": [
"fs/smb/server/smb2pdu.c",
"fs/smb/server/vfs.c"
],
"defaultStatus": "affected"
}
]
}
],
"published": "2026-08-15T06:17:48.460",
"references": [
{
"url": "https://git.kernel.org/stable/c/1e112c47ec5dd1942e2d4ca6e8e9b712238e20c2",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/a8c18434e1f0d9f7989170bdb0490c0160baf065",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
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"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
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"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/e205f3e7e8c31a47cd11efb6cf663a527177e432",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/fb1cae6302d58414ddf029e3f642711bd30243f7",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}
],
"vulnStatus": "Received",
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nksmbd: use opener credentials for FSCTL mutations\n\nSET_SPARSE, SET_ZERO_DATA and SET_COMPRESSION operate on an open SMB\nhandle but call VFS xattr, fallocate or fileattr helpers with the current\nksmbd worker credentials. Those helpers can revalidate inode permissions,\nownership and LSM policy independently of the SMB handle access mask.\n\nRun each operation with the credentials captured in the target file when\nthe handle was opened. Keep credential handling local to these single-file\nFSCTLs rather than applying session credentials to the complete IOCTL\nhandler, which also contains handle-less and multi-handle operations."
}
],
"lastModified": "2026-08-18T07:16:52.283",
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}