CVE-2026-23553

LOW

2.9

Descripcion

In the context switch logic Xen attempts to skip an IBPB in the case of a vCPU returning to a CPU on which it was the previous vCPU to run. While safe for Xen's isolation between vCPUs, this prevents the guest kernel correctly isolating between tasks. Consider: 1) vCPU runs on CPU A, running task 1. 2) vCPU moves to CPU B, idle gets scheduled on A. Xen skips IBPB. 3) On CPU B, guest kernel switches from task 1 to 2, issuing IBPB. 4) vCPU moves back to CPU A. Xen skips IBPB again. Now, task 2 is running on CPU A with task 1's training still in the BTB.

Detalles CVE

Puntuacion CVSS v3.12.9

SeveridadLOW

Vector CVSSCVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N

Vector de ataqueLOCAL

ComplejidadHIGH

Privilegios requeridosNONE

Interaccion usuarioNONE

Publicado1/28/2026

Ultima modificacion2/9/2026

Fuentenvd

Avistamientos honeypot0

Productos afectados

xen:xen

Debilidades (CWE)

CWE-665CWE-693

Referencias

https://xenbits.xenproject.org/xsa/advisory-479.html(security@xen.org)

http://www.openwall.com/lists/oss-security/2026/01/27/3(af854a3a-2127-422b-91ae-364da2661108)

http://xenbits.xen.org/xsa/advisory-479.html(af854a3a-2127-422b-91ae-364da2661108)

Correlaciones IOC

Sin correlaciones registradas

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