CVE-2026-63893
In the Linux kernel, the following vulnerability has been resolved:
thunderbolt: property: Reject u32 wrap in tb_property_entry_valid()
entry->value is u32 and entry->length is u16; the sum is performed in u32 and wraps. A malicious XDomain peer can pick value = 0xffffff00, length = 0x100 so the sum 0x100000000 wraps to 0 and passes the > block_len check. tb_property_parse() then passes entry->value to parse_dwdata() as a dword offset into the property block, reading attacker-directed memory far past the allocation.
For TEXT-typed entries with the "deviceid" or "vendorid" keys this lands in xd->device_name / xd->vendor_name and is readable back via the per-XDomain device_name / vendor_name sysfs attributes; the leak is NUL-bounded (kstrdup() stops at the first zero byte) and untargeted (the attacker picks a delta, not an absolute address).
Leer descripción completaMostrar menos
DATA-typed entries are parsed into property->value.data but not generically surfaced to userspace.
Use check_add_overflow() so a wrapped sum is rejected.
CVSS
- Versión: 3.1
- Vector: CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H
- Puntuación base: 8.1
Probabilidad de explotación (EPSS)
- Probabilidad de explotación en los próximos 30 días: 0.42%
- Percentil entre todas las CVEs puntuadas: 34
- 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
T1210Exploitation of Remote Serviceslateral movement85 % - Impacto principal
T1005Data from Local Systemcollection80 % - Impacto secundario
T1552.007Container APIcredential access75 %
Acceso desde par XDomain (red adyacente), explotando wrap de u32 para leer memoria arbitraria del kernel. Fuga de datos de deviceid/vendorid vía sysfs.
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/01deda0152066c6c955f0619114ea6afa070aaec
- https://git.kernel.org/stable/c/31b98e503ecca8077e5247253dd5425ab84bc96d
- https://git.kernel.org/stable/c/5c06a3043ad944f087bb2ae0aae28d820bb9f460
- https://git.kernel.org/stable/c/6a63623621639acbb39bc2d9fb09559681716695
- https://git.kernel.org/stable/c/8d4a758b407ab3de3be86d1ceadfa35d717d30c7
- https://git.kernel.org/stable/c/9fee50c4e1e42f6d3cbe30df584f9f648f626071
- https://git.kernel.org/stable/c/a47784aee77f33f786dc5d7375db821bdae68792
- https://git.kernel.org/stable/c/e8a0b0a93a6ef958e70b1dd4930beb6dc0026b36
JSON original (NVD)
Mostrar
{
"id": "CVE-2026-63893",
"cveTags": [],
"metrics": {
"cvssMetricV31": [
{
"type": "Secondary",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"cvssData": {
"scope": "UNCHANGED",
"version": "3.1",
"baseScore": 8.1,
"attackVector": "ADJACENT_NETWORK",
"baseSeverity": "HIGH",
"vectorString": "CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H",
"integrityImpact": "NONE",
"userInteraction": "NONE",
"attackComplexity": "LOW",
"availabilityImpact": "HIGH",
"privilegesRequired": "NONE",
"confidentialityImpact": "HIGH"
},
"impactScore": 5.2,
"exploitabilityScore": 2.8
}
]
},
"affected": [
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"affectedData": [
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"vendor": "Linux",
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"programFiles": [
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],
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},
{
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"vendor": "Linux",
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{
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},
{
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"version": "0",
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},
{
"status": "unaffected",
"version": "5.10.259",
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{
"status": "unaffected",
"version": "5.15.210",
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},
{
"status": "unaffected",
"version": "6.1.176",
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},
{
"status": "unaffected",
"version": "6.6.143",
"versionType": "semver",
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},
{
"status": "unaffected",
"version": "6.12.93",
"versionType": "semver",
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},
{
"status": "unaffected",
"version": "6.18.35",
"versionType": "semver",
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},
{
"status": "unaffected",
"version": "7.0.12",
"versionType": "semver",
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},
{
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"version": "7.1",
"versionType": "original_commit_for_fix",
"lessThanOrEqual": "*"
}
],
"programFiles": [
"drivers/thunderbolt/property.c"
],
"defaultStatus": "affected"
}
]
}
],
"published": "2026-07-19T16:17:06.710",
"references": [
{
"url": "https://git.kernel.org/stable/c/01deda0152066c6c955f0619114ea6afa070aaec",
"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/6a63623621639acbb39bc2d9fb09559681716695",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/8d4a758b407ab3de3be86d1ceadfa35d717d30c7",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/9fee50c4e1e42f6d3cbe30df584f9f648f626071",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
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"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/e8a0b0a93a6ef958e70b1dd4930beb6dc0026b36",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}
],
"vulnStatus": "Awaiting Analysis",
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nthunderbolt: property: Reject u32 wrap in tb_property_entry_valid()\n\nentry->value is u32 and entry->length is u16; the sum is performed in\nu32 and wraps. A malicious XDomain peer can pick\nvalue = 0xffffff00, length = 0x100 so the sum 0x100000000 wraps to 0\nand passes the > block_len check. tb_property_parse() then passes\nentry->value to parse_dwdata() as a dword offset into the property\nblock, reading attacker-directed memory far past the allocation.\n\nFor TEXT-typed entries with the \"deviceid\" or \"vendorid\" keys this\nlands in xd->device_name / xd->vendor_name and is readable back via\nthe per-XDomain device_name / vendor_name sysfs attributes; the leak\nis NUL-bounded (kstrdup() stops at the first zero byte) and\nuntargeted (the attacker picks a delta, not an absolute address).\nDATA-typed entries are parsed into property->value.data but not\ngenerically surfaced to userspace.\n\nUse check_add_overflow() so a wrapped sum is rejected."
}
],
"lastModified": "2026-07-27T17:44:23.777",
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}