CVE-2015-8555

high
Published 2016-04-13 · Modified 2026-05-06
CVSS v3
8.6
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:N
CVSS v2
5.0
VIR risk
8.6

Description

Xen 4.6.x, 4.5.x, 4.4.x, 4.3.x, and earlier do not initialize x86 FPU stack and XMM registers when XSAVE/XRSTOR are not used to manage guest extended register state, which allows local guest domains to obtain sensitive information from other domains via unspecified vectors.

Predictions

Exploit likelihood
91%
Patch ETA

Heuristic predictions, AS-IS, for prioritization only.

Mitigations

vendor Authored 2026-05-27

Vendor advisory: debian — https://security-tracker.debian.org/tracker/CVE-2015-8555

vendor Authored 2026-05-27

Vendor advisory: cve@mitre.org — http://xenbits.xen.org/xsa/advisory-165.html

OS impact

OSVersionStatusFixed in
debian debianbookwormfixed4.8.0~rc3-1
debian debianbullseyefixed4.8.0~rc3-1
debian debianforkyfixed4.8.0~rc3-1
debian debiansidfixed4.8.0~rc3-1
debian debiantrixiefixed4.8.0~rc3-1

Application impact

VendorProductVersionsFixed
citrixxenserver6.0

References

CWEs

CWE-200

Verify integrity in audit chain (admin only). AS-IS.