CVE-2016-7777

Name: CVE-2016-7777
Creator: NVD / NIST
Published: 2016-10-07T14:59:10.287+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

UnknownEPSS 0.30%

Last modified Jun 17, 2026

CVE-2016-7777 is a vulnerability of currently unknown severity. Xen 4.7.x and earlier does not properly honor CR0.TS and CR0.EM, which allows local x86 HVM guest OS users to read or modify FPU, MMX, or XMM register state information belonging to arbitrary tasks on the guest by modifying an instruction while the hypervisor is preparing to emulate it.. EPSS estimates a 0.30% chance of exploitation in the next 30 days.

Description

Xen 4.7.x and earlier does not properly honor CR0.TS and CR0.EM, which allows local x86 HVM guest OS users to read or modify FPU, MMX, or XMM register state information belonging to arbitrary tasks on the guest by modifying an instruction while the hypervisor is preparing to emulate it.

Metrics

EPSS Probability

0.30%

22.0th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-362

Affected Software

Vendor	Product	Versions
Xen	Xen	<= 4.7.0

References

http://www.securityfocus.com/bid/93344Third Party Advisory, VDB Entry
http://www.securitytracker.com/id/1036942Third Party Advisory, VDB Entry
http://xenbits.xen.org/xsa/advisory-190.htmlMitigation, Patch, Vendor Advisory
https://security.gentoo.org/glsa/201611-09
https://support.citrix.com/article/CTX217363
http://www.securityfocus.com/bid/93344Third Party Advisory, VDB Entry
http://www.securitytracker.com/id/1036942Third Party Advisory, VDB Entry
http://xenbits.xen.org/xsa/advisory-190.htmlMitigation, Patch, Vendor Advisory
https://security.gentoo.org/glsa/201611-09
https://support.citrix.com/article/CTX217363

Timeline

Published: Oct 7, 2016
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2016-7777?

How severe is CVE-2016-7777?

Severity scoring for CVE-2016-7777 is pending analysis. The EPSS model estimates a 0.30% probability of exploitation in the next 30 days.

How do I fix CVE-2016-7777?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2016-7777?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST