CVE-2026-31484

Estado: AnalizadaAlta (7.1)—

In the Linux kernel, the following vulnerability has been resolved:

io_uring/fdinfo: fix OOB read in SQE_MIXED wrap check

__io_uring_show_fdinfo() iterates over pending SQEs and, for 128-byte SQEs on an IORING_SETUP_SQE_MIXED ring, needs to detect when the second half of the SQE would be past the end of the sq_sqes array. The current check tests (++sq_head & sq_mask) == 0, but sq_head is only incremented when a 128-byte SQE is encountered, not on every iteration. The actual array index is sq_idx = (i + sq_head) & sq_mask, which can be sq_mask (the last slot) while the wrap check passes.

Fix by checking sq_idx directly. Keep the sq_head increment so the loop still skips the second half of the 128-byte SQE on the next iteration.

CVSS

Versión: 3.1
Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H
Puntuación base: 7.1

Probabilidad de explotación (EPSS)

Probabilidad de explotación en los próximos 30 días: 0.16%
Percentil entre todas las CVEs puntuadas: 4
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.

ExplotaciónT1068 Exploitation for Privilege Escalationprivilege escalation85 %
Impacto principalT1059 Command and Scripting Interpreterexecution60 %

Vulnerabilidad de lectura fuera de límites (CWE-125) en kernel Linux con acceso local y privilegios limitados (PR:L). Permite escalada de privilegios mediante corrupción de memoria en io_uring. Impacto: potencial ejecución de código con permisos elevados.

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

Execution Prevention Threat Intelligence Program Restrict Web-Based Content Privileged Account Management Limit Software Installation Behavior Prevention on Endpoint

Tecnologías afectadas (1)

Linux — Linux Kernel

CWE

CWE-125

Referencias

JSON original (NVD)

Mostrar

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      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nio_uring/fdinfo: fix OOB read in SQE_MIXED wrap check\n\n__io_uring_show_fdinfo() iterates over pending SQEs and, for 128-byte\nSQEs on an IORING_SETUP_SQE_MIXED ring, needs to detect when the second\nhalf of the SQE would be past the end of the sq_sqes array. The current\ncheck tests (++sq_head & sq_mask) == 0, but sq_head is only incremented\nwhen a 128-byte SQE is encountered, not on every iteration. The actual\narray index is sq_idx = (i + sq_head) & sq_mask, which can be sq_mask\n(the last slot) while the wrap check passes.\n\nFix by checking sq_idx directly. Keep the sq_head increment so the loop\nstill skips the second half of the 128-byte SQE on the next iteration."
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