CVE-2026-64034
In the Linux kernel, the following vulnerability has been resolved:
net: mana: Fix TOCTOU double-fetch of hwc_msg_id from DMA buffer
In mana_hwc_rx_event_handler(), resp->response.hwc_msg_id is read from DMA-coherent memory and bounds-checked, then mana_hwc_handle_resp() re-reads the same field from the same DMA buffer for test_bit() and pointer arithmetic.
DMA-coherent memory is mapped uncacheable on x86 and is shared, unencrypted, in Confidential VMs (SEV-SNP/TDX), so each load goes directly to host-visible memory. A H/W can modify the value between the check and the use, bypassing the bounds validation.
Leer descripción completaMostrar menos
Fix this by reading hwc_msg_id exactly once using READ_ONCE() into a stack-local variable in mana_hwc_rx_event_handler(), and passing the validated value as a parameter to mana_hwc_handle_resp().
CVSS
- Versión: 3.1
- Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
- Puntuación base: 9.3
Probabilidad de explotación (EPSS)
- Probabilidad de explotación en los próximos 30 días: 0.15%
- Percentil entre todas las CVEs puntuadas: 4
- 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 secundario
T1499.004Application or System Exploitationimpact65 % - Impacto secundario
T1565.001Stored Data Manipulationimpact70 %
TOCTOU en kernel Linux (AV:L, PR:N, UI:N) permite escalada de privilegios local. El atacante modifica DMA-buffer entre validación y uso, logrando ejecución de código, corrupción de datos y denegación de servicio (impacto crítico: C:H, I:H, 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/09ec063d87c2dd3fa6f3561361a017bd882e9f37
- https://git.kernel.org/stable/c/35f0f0a2536a4d604b4dbad92c85c4a8fdebb870
- https://git.kernel.org/stable/c/3c4db56ccd13dd020fbf43afabaee74a40ec75e4
- https://git.kernel.org/stable/c/566f42fb67a7ebfed6650e407e5b72e6b3e83bf7
- https://git.kernel.org/stable/c/6180a06bbc99fd9114b8db4be6c4d46e40f046ef
- https://git.kernel.org/stable/c/70ad2dff8d052a85dfef15715b531f38a29108cf
- https://git.kernel.org/stable/c/a201c66edf2ebc6cfdc3813a889ba20fecebfae3
JSON original (NVD)
Mostrar
{
"id": "CVE-2026-64034",
"cveTags": [],
"metrics": {
"cvssMetricV31": [
{
"type": "Secondary",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"cvssData": {
"scope": "CHANGED",
"version": "3.1",
"baseScore": 9.3,
"attackVector": "LOCAL",
"baseSeverity": "CRITICAL",
"vectorString": "CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H",
"integrityImpact": "HIGH",
"userInteraction": "NONE",
"attackComplexity": "LOW",
"availabilityImpact": "HIGH",
"privilegesRequired": "NONE",
"confidentialityImpact": "HIGH"
},
"impactScore": 6,
"exploitabilityScore": 2.5
}
]
},
"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": "ca9c54d2d6a5ab2430c4eda364c77125d62e5e0f",
"lessThan": "a201c66edf2ebc6cfdc3813a889ba20fecebfae3",
"versionType": "git"
},
{
"status": "affected",
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"versionType": "git"
},
{
"status": "affected",
"version": "ca9c54d2d6a5ab2430c4eda364c77125d62e5e0f",
"lessThan": "566f42fb67a7ebfed6650e407e5b72e6b3e83bf7",
"versionType": "git"
},
{
"status": "affected",
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"versionType": "git"
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{
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"status": "affected",
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"versionType": "git"
},
{
"status": "affected",
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"versionType": "git"
}
],
"programFiles": [
"drivers/net/ethernet/microsoft/mana/hw_channel.c"
],
"defaultStatus": "unaffected"
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "5.13"
},
{
"status": "unaffected",
"version": "0",
"lessThan": "5.13",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "5.15.209",
"versionType": "semver",
"lessThanOrEqual": "5.15.*"
},
{
"status": "unaffected",
"version": "6.1.175",
"versionType": "semver",
"lessThanOrEqual": "6.1.*"
},
{
"status": "unaffected",
"version": "6.6.142",
"versionType": "semver",
"lessThanOrEqual": "6.6.*"
},
{
"status": "unaffected",
"version": "6.12.92",
"versionType": "semver",
"lessThanOrEqual": "6.12.*"
},
{
"status": "unaffected",
"version": "6.18.34",
"versionType": "semver",
"lessThanOrEqual": "6.18.*"
},
{
"status": "unaffected",
"version": "7.0.11",
"versionType": "semver",
"lessThanOrEqual": "7.0.*"
},
{
"status": "unaffected",
"version": "7.1",
"versionType": "original_commit_for_fix",
"lessThanOrEqual": "*"
}
],
"programFiles": [
"drivers/net/ethernet/microsoft/mana/hw_channel.c"
],
"defaultStatus": "affected"
}
]
}
],
"published": "2026-07-19T16:17:43.620",
"references": [
{
"url": "https://git.kernel.org/stable/c/09ec063d87c2dd3fa6f3561361a017bd882e9f37",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/35f0f0a2536a4d604b4dbad92c85c4a8fdebb870",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/3c4db56ccd13dd020fbf43afabaee74a40ec75e4",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/566f42fb67a7ebfed6650e407e5b72e6b3e83bf7",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/6180a06bbc99fd9114b8db4be6c4d46e40f046ef",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/70ad2dff8d052a85dfef15715b531f38a29108cf",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/a201c66edf2ebc6cfdc3813a889ba20fecebfae3",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}
],
"vulnStatus": "Awaiting Analysis",
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet: mana: Fix TOCTOU double-fetch of hwc_msg_id from DMA buffer\n\nIn mana_hwc_rx_event_handler(), resp->response.hwc_msg_id is read from\nDMA-coherent memory and bounds-checked, then mana_hwc_handle_resp()\nre-reads the same field from the same DMA buffer for test_bit() and\npointer arithmetic.\n\nDMA-coherent memory is mapped uncacheable on x86 and is shared,\nunencrypted, in Confidential VMs (SEV-SNP/TDX), so each load goes\ndirectly to host-visible memory. A H/W can modify the value\nbetween the check and the use, bypassing the bounds validation.\n\nFix this by reading hwc_msg_id exactly once using READ_ONCE() into a\nstack-local variable in mana_hwc_rx_event_handler(), and passing the\nvalidated value as a parameter to mana_hwc_handle_resp()."
}
],
"lastModified": "2026-07-30T14:59:47.950",
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}