CVE-2015-8555

Severity: high (CVSS 8.6 v3.0)
Exploited in the wild: not listed in CISA KEV
EPSS: 2.3% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2016-04-13 · updated 2026-06-17
Weakness: CWE-200

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.

Affected products

Citrix XenServer: 6.0 (and their updates)
xen: 4.3.0, 4.3.1, 4.3.2, 4.3.3, 4.3.4, 4.4.0 (+10) (and their updates)

References

http://support.citrix.com/article/CTX203879
http://www.debian.org/security/2016/dsa-3519
http://www.oracle.com/technetwork/topics/security/ovmbulletinjul2016-3090546.html
http://www.securityfocus.com/bid/79543
http://www.securitytracker.com/id/1034477
http://xenbits.xen.org/xsa/advisory-165.html
https://security.gentoo.org/glsa/201604-03
http://support.citrix.com/article/CTX203879
http://www.debian.org/security/2016/dsa-3519
http://www.oracle.com/technetwork/topics/security/ovmbulletinjul2016-3090546.html
http://www.securityfocus.com/bid/79543
http://www.securitytracker.com/id/1034477

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