CVE-2026-68137
Estado: RecibidaCrítica (9.8)—
In the Linux kernel, the following vulnerability has been resolved:
net/x25: fix use-after-free in x25_kill_by_neigh()
x25_kill_by_neigh() walks the global X.25 socket list looking for sockets attached to a terminating neighbour. x25_list_lock protects list membership while the lookup is in progress, but it does not pin a socket's lifetime after the lock is dropped.
The function currently drops x25_list_lock before calling lock_sock(s). A concurrent close can run x25_release(), remove the same socket from x25_list, and drop the last socket reference in that window. The neighbour teardown path can then lock or inspect a freed struct sock/struct x25_sock.
Leer descripción completaMostrar menos
Take sock_hold(s) while x25_list_lock still proves that the list entry is live, then drop the temporary reference after the socket has been locked, rechecked, and released. Recheck x25_sk(s)->neighbour after lock_sock(), because another path may have disconnected the socket before this path acquired the socket lock. Restart the list walk after each disconnect because the list lock was dropped and the previous iterator state may no longer be valid.
A QEMU/KASAN run against origin/master reproduced a slab-use-after-free in x25_kill_by_neigh().
CVSS
- Versión: 3.1
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- Puntuación base: 9.8
Probabilidad de explotación (EPSS)
- Probabilidad de explotación en los próximos 30 días: 0.73%
- Percentil entre todas las CVEs puntuadas: 53
- Fecha de la puntuación: 5/10/2026
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
T1190Exploit Public-Facing Applicationinitial access45 % - Impacto principal
T1499.004Application or System Exploitationimpact70 %
Vulnerabilidad de use-after-free en kernel X.25 accesible remotamente (AV:N, PR:N, UI:N) permite DoS por corrupción de memoria y potencial escalada de privilegios en contexto kernel.
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/3f4fe26c20c30bd5a2e2583e80685def0b27858c
- https://git.kernel.org/stable/c/5499e0602d2faafd42c580d25f615903c3fbe11b
- https://git.kernel.org/stable/c/5e8a754ac2009a88a7b99ab61eab6296eed360f3
- https://git.kernel.org/stable/c/610678d4be94b619c751572e8a58de705592cd07
- https://git.kernel.org/stable/c/9aabda553184346f74810e2ee1d96920b4612e3f
- https://git.kernel.org/stable/c/c98a454d1a9e1bd09d5fd55a7aa589b199340b88
- https://git.kernel.org/stable/c/db6b04f6d65549bb1c7bc8e64a92e7b7d03be676
- https://git.kernel.org/stable/c/ec6d91a1bf2ebd767d3d43f6d249ee0ed3f4558a
JSON original (NVD)
Mostrar
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],
"vulnStatus": "Received",
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet/x25: fix use-after-free in x25_kill_by_neigh()\n\nx25_kill_by_neigh() walks the global X.25 socket list looking for sockets\nattached to a terminating neighbour. x25_list_lock protects list membership\nwhile the lookup is in progress, but it does not pin a socket's lifetime\nafter the lock is dropped.\n\nThe function currently drops x25_list_lock before calling lock_sock(s). A\nconcurrent close can run x25_release(), remove the same socket from\nx25_list, and drop the last socket reference in that window. The neighbour\nteardown path can then lock or inspect a freed struct sock/struct x25_sock.\n\nTake sock_hold(s) while x25_list_lock still proves that the list entry is\nlive, then drop the temporary reference after the socket has been locked,\nrechecked, and released. Recheck x25_sk(s)->neighbour after lock_sock(),\nbecause another path may have disconnected the socket before this path\nacquired the socket lock. Restart the list walk after each disconnect\nbecause the list lock was dropped and the previous iterator state may no\nlonger be valid.\n\nA QEMU/KASAN run against origin/master reproduced a slab-use-after-free in\nx25_kill_by_neigh()."
}
],
"lastModified": "2026-08-19T17:20:30.880",
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}