CVE-2026-98568
En el kernel de Linux se ha resuelto la siguiente vulnerabilidad:
vxlan: usar una única instantánea del headroom para las respuestas de vecino
vxlan_na_create() consulta LL_RESERVED_SPACE() para dimensionar el skb de respuesta y, a continuación, vuelve a consultarlo para reservar el headroom. Una llamada concurrente a vxlan_changelink() puede actualizar needed_headroom entre las dos lecturas, lo que genera una condición de carrera TOCTOU. El segundo valor puede superar el tamaño asignado y hacer que la escritura de la cabecera Ethernet se salga de los límites.
La condición de carrera es reproducible en el kernel sin parchear. Se produjo cuando vxlan_na_create() generaba una respuesta de vecino mientras vxlan_changelink() modificaba el headroom del enlace.
Leer descripción completaMostrar menos
KASAN detectó una escritura de cuatro bytes situada dos bytes más allá de una asignación skbuff_small_head de 704 bytes.
Tomar una única instantánea del headroom y usar ese valor tanto para la asignación como para la reserva.
Traducción automática del texto original de NVD (en inglés).
CVSS
NVD no ha asignado puntuación CVSS a esta CVE (habitual desde el cambio de política de abril de 2026).
Probabilidad de explotación (EPSS)
- Probabilidad de explotación en los próximos 30 días
- 0.20 %
- Percentil entre todas las CVEs puntuadas
- 9
- Fecha de la puntuación
- 20/10/2026
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).
Tecnologías afectadas (1)
⚠ Inferidas por IA a partir de la descripción — NVD aún no ha analizado esta CVE; no son CPE verificados.
Referencias
Mostrar las 5 referencias
- https://git.kernel.org/stable/c/315d42ca39f69846662961c25dcf2bb07c350d14
- https://git.kernel.org/stable/c/45a67662bf8ce3aa5643accf98d328dfbb47eaf6
- https://git.kernel.org/stable/c/481506a756dcd828ef42391cb08f38d8d96d38fc
- https://git.kernel.org/stable/c/a3c5eb6e382dd426a5e7eb08608897ed57167ff7
- https://git.kernel.org/stable/c/ff022fd9d0f0282c575e11778b96bd1b637503eb
JSON original (NVD)
Mostrar
{
"id": "CVE-2026-98568",
"cveTags": [],
"metrics": {},
"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": "4b29dba9c085a4fb79058fb1c45a2f6257ca3dfa",
"lessThan": "45a67662bf8ce3aa5643accf98d328dfbb47eaf6",
"versionType": "git"
},
{
"status": "affected",
"version": "4b29dba9c085a4fb79058fb1c45a2f6257ca3dfa",
"lessThan": "315d42ca39f69846662961c25dcf2bb07c350d14",
"versionType": "git"
},
{
"status": "affected",
"version": "4b29dba9c085a4fb79058fb1c45a2f6257ca3dfa",
"lessThan": "a3c5eb6e382dd426a5e7eb08608897ed57167ff7",
"versionType": "git"
},
{
"status": "affected",
"version": "4b29dba9c085a4fb79058fb1c45a2f6257ca3dfa",
"lessThan": "ff022fd9d0f0282c575e11778b96bd1b637503eb",
"versionType": "git"
},
{
"status": "affected",
"version": "4b29dba9c085a4fb79058fb1c45a2f6257ca3dfa",
"lessThan": "481506a756dcd828ef42391cb08f38d8d96d38fc",
"versionType": "git"
},
{
"status": "affected",
"version": "d8be18c52dbc94989f6d74637b731af39cd3d902",
"versionType": "git"
},
{
"status": "affected",
"version": "3927dace523706cc00f808520eaf2125dd7c07b5",
"versionType": "git"
},
{
"status": "affected",
"version": "3.12.18",
"lessThan": "3.13",
"versionType": "semver"
},
{
"status": "affected",
"version": "3.13.10",
"lessThan": "3.14",
"versionType": "semver"
}
],
"programFiles": [
"drivers/net/vxlan/vxlan_core.c"
],
"defaultStatus": "unaffected"
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "3.14"
},
{
"status": "unaffected",
"version": "0",
"lessThan": "3.14",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "6.6.158",
"versionType": "semver",
"lessThanOrEqual": "6.6.*"
},
{
"status": "unaffected",
"version": "6.12.112",
"versionType": "semver",
"lessThanOrEqual": "6.12.*"
},
{
"status": "unaffected",
"version": "6.18.55",
"versionType": "semver",
"lessThanOrEqual": "6.18.*"
},
{
"status": "unaffected",
"version": "7.2.9",
"versionType": "semver",
"lessThanOrEqual": "7.2.*"
},
{
"status": "unaffected",
"version": "7.3",
"versionType": "original_commit_for_fix",
"lessThanOrEqual": "*"
}
],
"programFiles": [
"drivers/net/vxlan/vxlan_core.c"
],
"defaultStatus": "affected"
}
]
}
],
"published": "2026-10-18T16:17:09.000",
"references": [
{
"url": "https://git.kernel.org/stable/c/315d42ca39f69846662961c25dcf2bb07c350d14",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/45a67662bf8ce3aa5643accf98d328dfbb47eaf6",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/481506a756dcd828ef42391cb08f38d8d96d38fc",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/a3c5eb6e382dd426a5e7eb08608897ed57167ff7",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/ff022fd9d0f0282c575e11778b96bd1b637503eb",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}
],
"vulnStatus": "Received",
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nvxlan: use one headroom snapshot for neighbour replies\n\nvxlan_na_create() samples LL_RESERVED_SPACE() to size the reply skb and then\nsamples it again to reserve headroom. A concurrent vxlan_changelink() can\nupdate needed_headroom between the two reads, creating a TOCTOU race. The\nsecond value can exceed the allocation and make the Ethernet header write out\nof bounds.\n\nThe race is reproducible on the unpatched kernel. It occurred when\nvxlan_na_create() generated a neighbour reply while vxlan_changelink() changed\nthe link headroom. KASAN caught a four-byte write two bytes beyond a 704-byte\nskbuff_small_head allocation.\n\nSnapshot the headroom once and use that value for both allocation and\nreservation."
}
],
"lastModified": "2026-10-19T10:19:14.750",
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}