CVE-2026-63995
In the Linux kernel, the following vulnerability has been resolved:
ethtool: cmis: validate start_cmd_payload_size from module
The CMIS firmware update code reads start_cmd_payload_size from the module's FW Management Features CDB reply and uses it directly as the byte count for memcpy. The destination buffer is 112 bytes (ETHTOOL_CMIS_CDB_LPL_MAX_PL_LENGTH - 8). So a malicious module (or corrupted response) can cause a OOB write later on in cmis_fw_update_start_download().
Let's error out. If modules that expect longer LPL writes actually exist we should revisit.
struct cmis_cdb_start_fw_download_pl's definition has to move, no change there.
CVSS
- Versión: 3.1
- Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- Puntuación base: 7.8
Probabilidad de explotación (EPSS)
- Probabilidad de explotación en los próximos 30 días: 0.13%
- Percentil entre todas las CVEs puntuadas: 2
- 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
T1068Exploitation for Privilege Escalationprivilege escalation85 % - Impacto principal
T1059Command and Scripting Interpreterexecution75 % - Impacto secundario
T1565Data Manipulationimpact70 %
Acceso local (AV:L) sin interacción del usuario (UI:N) con privilegios (PR:L) permite escalada. OOB write en kernel da ejecución de código y manipulación de memoria.
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
JSON original (NVD)
Mostrar
{
"id": "CVE-2026-63995",
"cveTags": [],
"metrics": {
"cvssMetricV31": [
{
"type": "Secondary",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"cvssData": {
"scope": "UNCHANGED",
"version": "3.1",
"baseScore": 7.8,
"attackVector": "LOCAL",
"baseSeverity": "HIGH",
"vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
"integrityImpact": "HIGH",
"userInteraction": "NONE",
"attackComplexity": "LOW",
"availabilityImpact": "HIGH",
"privilegesRequired": "LOW",
"confidentialityImpact": "HIGH"
},
"impactScore": 5.9,
"exploitabilityScore": 1.8
}
]
},
"affected": [
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"affectedData": [
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "c4f78134d45c9619339c96b4bea380b1d0699788",
"lessThan": "63112b4515469d00008452d9cfe3fb3bf1aa2df3",
"versionType": "git"
},
{
"status": "affected",
"version": "c4f78134d45c9619339c96b4bea380b1d0699788",
"lessThan": "0696709e951be54c699664adf546d16e28974d53",
"versionType": "git"
},
{
"status": "affected",
"version": "c4f78134d45c9619339c96b4bea380b1d0699788",
"lessThan": "a46340da00385be7fb16c62425ebc20006f2d5d8",
"versionType": "git"
},
{
"status": "affected",
"version": "c4f78134d45c9619339c96b4bea380b1d0699788",
"lessThan": "12c2496a71f82f63617971ca9b730dffa05cf58b",
"versionType": "git"
}
],
"programFiles": [
"net/ethtool/cmis_fw_update.c"
],
"defaultStatus": "unaffected"
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "6.11"
},
{
"status": "unaffected",
"version": "0",
"lessThan": "6.11",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "6.12.93",
"versionType": "semver",
"lessThanOrEqual": "6.12.*"
},
{
"status": "unaffected",
"version": "6.18.35",
"versionType": "semver",
"lessThanOrEqual": "6.18.*"
},
{
"status": "unaffected",
"version": "7.0.12",
"versionType": "semver",
"lessThanOrEqual": "7.0.*"
},
{
"status": "unaffected",
"version": "7.1",
"versionType": "original_commit_for_fix",
"lessThanOrEqual": "*"
}
],
"programFiles": [
"net/ethtool/cmis_fw_update.c"
],
"defaultStatus": "affected"
}
]
}
],
"published": "2026-07-19T16:17:39.067",
"references": [
{
"url": "https://git.kernel.org/stable/c/0696709e951be54c699664adf546d16e28974d53",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/12c2496a71f82f63617971ca9b730dffa05cf58b",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/63112b4515469d00008452d9cfe3fb3bf1aa2df3",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/a46340da00385be7fb16c62425ebc20006f2d5d8",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}
],
"vulnStatus": "Awaiting Analysis",
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nethtool: cmis: validate start_cmd_payload_size from module\n\nThe CMIS firmware update code reads start_cmd_payload_size from\nthe module's FW Management Features CDB reply and uses it directly\nas the byte count for memcpy. The destination buffer is 112 bytes\n(ETHTOOL_CMIS_CDB_LPL_MAX_PL_LENGTH - 8). So a malicious\nmodule (or corrupted response) can cause a OOB write later on in\ncmis_fw_update_start_download().\n\nLet's error out. If modules that expect longer LPL writes actually\nexist we should revisit.\n\nstruct cmis_cdb_start_fw_download_pl's definition has to move,\nno change there."
}
],
"lastModified": "2026-07-30T14:51:11.223",
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}