CVE-2026-23553

LOW

2.9

Descricao

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.

Detalhes CVE

Pontuacao CVSS v3.12.9

SeveridadeLOW

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

Vetor de ataqueLOCAL

ComplexidadeHIGH

Privilegios necessariosNONE

Interacao do usuarioNONE

Publicado1/28/2026

Ultima modificacao2/9/2026

Fontenvd

Avistamentos honeypot0

Produtos afetados

xen:xen

Fraquezas (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)

Correlacoes IOC

Sem correlacoes registradas

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