CVE-2026-63874
In the Linux kernel, the following vulnerability has been resolved:
net: mctp: usb: fix race between urb completion and rx_retry cancellation
It's possible that sequencing between setting ->stopped and cancelling the rx_retry work (in ndo_stop) could leave us with an urb queued:
That urb completion can then re-schedule rx_retry_work.
Strenghen the sequencing between the stop (preventing another requeue) and the cancel by updating both atomically under a new rx lock. After setting ->rx_stopped, and cancelling pending work, we know that the requeue cannot occur, so all that's left is killing any pending urb.
Detalles técnicos trazas, registros y código del informe original
T1: ndo_stop T2: rx_retry_work
------------ ----------------
LD: ->stopped => false
ST: ->stopped <= true
usb_kill_urb()
mctp_usb_rx_queue()
usb_submit_urb()
cancel_delayed_work_sync()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 escalation75 % - Impacto principal
T1499.004Application or System Exploitationimpact60 %
Vulnerabilidad de race condition en kernel Linux con acceso local (AV:L, PR:L) que afecta a dispositivos USB/MCTP, permitiendo DoS por urb queued no controlado; sin impacto de ejecución explícito.
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-2026-63874",
"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": "0791c0327a6e4e7691d6fc5ad334c215de04dcc9",
"lessThan": "9c46f3ee1837f6881cb99a52ffecb2760f11dc73",
"versionType": "git"
},
{
"status": "affected",
"version": "0791c0327a6e4e7691d6fc5ad334c215de04dcc9",
"lessThan": "d90feaa3f74bea8dafb6494631a194c70e547d94",
"versionType": "git"
},
{
"status": "affected",
"version": "0791c0327a6e4e7691d6fc5ad334c215de04dcc9",
"lessThan": "54665dce982689e2fd99b32e9a0dcc204fda8a51",
"versionType": "git"
}
],
"programFiles": [
"drivers/net/mctp/mctp-usb.c"
],
"defaultStatus": "unaffected"
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "6.15"
},
{
"status": "unaffected",
"version": "0",
"lessThan": "6.15",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "6.18.36",
"versionType": "semver",
"lessThanOrEqual": "6.18.*"
},
{
"status": "unaffected",
"version": "7.0.13",
"versionType": "semver",
"lessThanOrEqual": "7.0.*"
},
{
"status": "unaffected",
"version": "7.1",
"versionType": "original_commit_for_fix",
"lessThanOrEqual": "*"
}
],
"programFiles": [
"drivers/net/mctp/mctp-usb.c"
],
"defaultStatus": "affected"
}
]
}
],
"published": "2026-07-19T15:16:54.450",
"references": [
{
"url": "https://git.kernel.org/stable/c/54665dce982689e2fd99b32e9a0dcc204fda8a51",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/9c46f3ee1837f6881cb99a52ffecb2760f11dc73",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/d90feaa3f74bea8dafb6494631a194c70e547d94",
"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: mctp: usb: fix race between urb completion and rx_retry cancellation\n\nIt's possible that sequencing between setting ->stopped and cancelling\nthe rx_retry work (in ndo_stop) could leave us with an urb queued:\n\n T1: ndo_stop T2: rx_retry_work\n ------------ ----------------\n LD: ->stopped => false\n ST: ->stopped <= true\n usb_kill_urb()\n mctp_usb_rx_queue()\n usb_submit_urb()\n cancel_delayed_work_sync()\n\nThat urb completion can then re-schedule rx_retry_work.\n\nStrenghen the sequencing between the stop (preventing another requeue)\nand the cancel by updating both atomically under a new rx lock. After\nsetting ->rx_stopped, and cancelling pending work, we know that the\nrequeue cannot occur, so all that's left is killing any pending urb."
}
],
"lastModified": "2026-07-27T17:44:23.777",
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}