CVE-2026-23553

LOW

2.9

Beschreibung

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.

CVE Details

CVSS v3.1 Bewertung2.9

SchweregradLOW

CVSS VektorCVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N

AngriffsvektorLOCAL

KomplexitatHIGH

Erforderliche PrivilegienNONE

BenutzerinteraktionNONE

Veroffentlicht1/28/2026

Zuletzt geandert2/9/2026

Quellenvd

Honeypot-Sichtungen0

Betroffene Produkte

xen:xen

Schwachen (CWE)

CWE-665CWE-693

Referenzen

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)

IOC Korrelationen

Keine Korrelationen erfasst

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