CVE-2026-64540
Estado: RecibidaAlta (8.1)—
In the Linux kernel, the following vulnerability has been resolved:
usbnet: gl620a: fix out-of-bounds read in genelink_rx_fixup()
genelink_rx_fixup() splits an aggregated RX frame into its individual packets, using a per-packet length taken from device-supplied data. That length is only bounded by GL_MAX_PACKET_LEN (1514); it is never compared against how many bytes were actually received.
A malicious GeneLink (GL620A) device can therefore send a short URB whose header claims packet_count > 1 and a first packet of up to 1514 bytes.
then copies past the end of the receive buffer and hands the adjacent slab contents up the network stack, an out-of-bounds read that leaks kernel heap. No privilege is required: the path runs in the usbnet RX softirq as soon as the interface is up.
Leer descripción completaMostrar menos
skb_pull() already verifies that the requested length fits the buffer and returns NULL otherwise. Move it ahead of the copy and check its result, so a packet that overruns the received data is rejected before it is read. Well-formed frames, whose packets are fully present, are unaffected.
Detalles técnicos trazas, registros y código del informe original
skb_put_data(gl_skb, packet->packet_data, size);
BUG: KASAN: slab-out-of-bounds in genelink_rx_fixup (drivers/net/usb/gl620a.c:112)
Read of size 1514 at addr ffff888011309708 by task ksoftirqd/0/14
Call Trace:
...
__asan_memcpy (mm/kasan/shadow.c:105)
genelink_rx_fixup (include/linux/skbuff.h:2814 drivers/net/usb/gl620a.c:112)
usbnet_bh (drivers/net/usb/usbnet.c:572 drivers/net/usb/usbnet.c:1589)
process_one_work (kernel/workqueue.c:3322)
bh_worker (kernel/workqueue.c:3405)
tasklet_action (kernel/softirq.c:965)
handle_softirqs (kernel/softirq.c:622)
run_ksoftirqd (kernel/softirq.c:1076)
...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 movement60 %
Inferido por reglas deterministas a partir del vector CVSS y la CWE. Solo orientativo.
🛡️ 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/0575599e451aff3c5329922562374a2cab25fc51
- https://git.kernel.org/stable/c/0a7d9c7c5f1f208c523abbb4db6aea7bc1fad3db
- https://git.kernel.org/stable/c/255d03551f94c7bdd86c7d9181a70b21917d829f
- https://git.kernel.org/stable/c/3ef79fa3860e644c8de7834fa7300e1c58f38862
- https://git.kernel.org/stable/c/4359376e6238d89977a35086e47ca3b07f43e850
- https://git.kernel.org/stable/c/573418f7ea8f859a841417eb4b915594094fd967
- https://git.kernel.org/stable/c/8624e179fa3ce23c2fbd1a198ce30764b73f054a
- https://git.kernel.org/stable/c/8ff7f2a6da4fccaa5cc9be7251a24e71e29fbd1a
JSON original (NVD)
Mostrar
{
"id": "CVE-2026-64540",
"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": [
{
"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": "47ee3051c856cc2aa95d35d577a8cb37279d540f",
"lessThan": "255d03551f94c7bdd86c7d9181a70b21917d829f",
"versionType": "git"
},
{
"status": "affected",
"version": "47ee3051c856cc2aa95d35d577a8cb37279d540f",
"lessThan": "4359376e6238d89977a35086e47ca3b07f43e850",
"versionType": "git"
},
{
"status": "affected",
"version": "47ee3051c856cc2aa95d35d577a8cb37279d540f",
"lessThan": "8624e179fa3ce23c2fbd1a198ce30764b73f054a",
"versionType": "git"
},
{
"status": "affected",
"version": "47ee3051c856cc2aa95d35d577a8cb37279d540f",
"lessThan": "573418f7ea8f859a841417eb4b915594094fd967",
"versionType": "git"
},
{
"status": "affected",
"version": "47ee3051c856cc2aa95d35d577a8cb37279d540f",
"lessThan": "0575599e451aff3c5329922562374a2cab25fc51",
"versionType": "git"
},
{
"status": "affected",
"version": "47ee3051c856cc2aa95d35d577a8cb37279d540f",
"lessThan": "0a7d9c7c5f1f208c523abbb4db6aea7bc1fad3db",
"versionType": "git"
},
{
"status": "affected",
"version": "47ee3051c856cc2aa95d35d577a8cb37279d540f",
"lessThan": "3ef79fa3860e644c8de7834fa7300e1c58f38862",
"versionType": "git"
},
{
"status": "affected",
"version": "47ee3051c856cc2aa95d35d577a8cb37279d540f",
"lessThan": "8ff7f2a6da4fccaa5cc9be7251a24e71e29fbd1a",
"versionType": "git"
}
],
"programFiles": [
"drivers/net/usb/gl620a.c"
],
"defaultStatus": "unaffected"
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "2.6.14"
},
{
"status": "unaffected",
"version": "0",
"lessThan": "2.6.14",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "5.10.261",
"versionType": "semver",
"lessThanOrEqual": "5.10.*"
},
{
"status": "unaffected",
"version": "5.15.212",
"versionType": "semver",
"lessThanOrEqual": "5.15.*"
},
{
"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",
"lessThanOrEqual": "6.18.*"
},
{
"status": "unaffected",
"version": "7.1.5",
"versionType": "semver",
"lessThanOrEqual": "7.1.*"
},
{
"status": "unaffected",
"version": "7.2",
"versionType": "original_commit_for_fix",
"lessThanOrEqual": "*"
}
],
"programFiles": [
"drivers/net/usb/gl620a.c"
],
"defaultStatus": "affected"
}
]
}
],
"published": "2026-07-27T21:17:06.407",
"references": [
{
"url": "https://git.kernel.org/stable/c/0575599e451aff3c5329922562374a2cab25fc51",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/0a7d9c7c5f1f208c523abbb4db6aea7bc1fad3db",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/255d03551f94c7bdd86c7d9181a70b21917d829f",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/3ef79fa3860e644c8de7834fa7300e1c58f38862",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/4359376e6238d89977a35086e47ca3b07f43e850",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/573418f7ea8f859a841417eb4b915594094fd967",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/8624e179fa3ce23c2fbd1a198ce30764b73f054a",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/8ff7f2a6da4fccaa5cc9be7251a24e71e29fbd1a",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}
],
"vulnStatus": "Received",
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nusbnet: gl620a: fix out-of-bounds read in genelink_rx_fixup()\n\ngenelink_rx_fixup() splits an aggregated RX frame into its individual\npackets, using a per-packet length taken from device-supplied data. That\nlength is only bounded by GL_MAX_PACKET_LEN (1514); it is never compared\nagainst how many bytes were actually received.\n\nA malicious GeneLink (GL620A) device can therefore send a short URB whose\nheader claims packet_count > 1 and a first packet of up to 1514 bytes.\n\n\tskb_put_data(gl_skb, packet->packet_data, size);\n\nthen copies past the end of the receive buffer and hands the adjacent slab\ncontents up the network stack, an out-of-bounds read that leaks kernel heap.\nNo privilege is required: the path runs in the usbnet RX softirq as soon as\nthe interface is up.\n\n BUG: KASAN: slab-out-of-bounds in genelink_rx_fixup (drivers/net/usb/gl620a.c:112)\n Read of size 1514 at addr ffff888011309708 by task ksoftirqd/0/14\n Call Trace:\n ...\n __asan_memcpy (mm/kasan/shadow.c:105)\n genelink_rx_fixup (include/linux/skbuff.h:2814 drivers/net/usb/gl620a.c:112)\n usbnet_bh (drivers/net/usb/usbnet.c:572 drivers/net/usb/usbnet.c:1589)\n process_one_work (kernel/workqueue.c:3322)\n bh_worker (kernel/workqueue.c:3405)\n tasklet_action (kernel/softirq.c:965)\n handle_softirqs (kernel/softirq.c:622)\n run_ksoftirqd (kernel/softirq.c:1076)\n ...\n\nskb_pull() already verifies that the requested length fits the buffer and\nreturns NULL otherwise. Move it ahead of the copy and check its result, so\na packet that overruns the received data is rejected before it is read.\nWell-formed frames, whose packets are fully present, are unaffected."
}
],
"lastModified": "2026-08-17T05:17:59.007",
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}