Access Restriction Bypass Affecting xen package, versions <4.2.0~rc2-1


Severity

Recommended
0.0
medium
0
10

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Threat Intelligence

EPSS
0.45% (36th percentile)

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  • Snyk IDSNYK-ECHOLATEST-XEN-18388621
  • published29 Jul 2026
  • disclosed1 Apr 2015

Introduced: 1 Apr 2015

CVE-2015-2756  (opens in a new tab)
CWE-264  (opens in a new tab)

How to fix?

Upgrade Echo:latest xen to version 4.2.0~rc2-1 or higher.

NVD Description

Note: Versions mentioned in the description apply only to the upstream xen package and not the xen package as distributed by Echo. See How to fix? for Echo:latest relevant fixed versions and status.

QEMU, as used in Xen 3.3.x through 4.5.x, does not properly restrict access to PCI command registers, which might allow local HVM guest users to cause a denial of service (non-maskable interrupt and host crash) by disabling the (1) memory or (2) I/O decoding for a PCI Express device and then accessing the device, which triggers an Unsupported Request (UR) response.

CVSS Base Scores

version 3.1