How severe is CVE-2016-3158?

CVE-2016-3158 has a CVSS 3.x base score of 3.8, rated low severity. It is exploitable over local access with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is low, integrity none, and availability none.

Is CVE-2016-3158 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (33rd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2016-3158?

CVE-2016-3158 primarily affects Xen. In total, 5 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2016-3158?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2016-3158 published?

CVE-2016-3158 was published on 2016-04-13 and last updated on 2026-06-17.

CVE-2016-3158

CVE-2016-3158 is a low-severity vulnerability in Xen with a CVSS 3.x base score of 3.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-200.

Key facts

Severity: Low (CVSS 3.x base score 3.8)
CVSS v2: 1.7
EPSS exploit prediction: 0% (33rd percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-200
Affected product: Xen
Published: 2016-04-13
Last modified: 2026-06-17

Description

The xrstor function in arch/x86/xstate.c in Xen 4.x does not properly handle writes to the hardware FSW.ES bit when running on AMD64 processors, which allows local guest OS users to obtain sensitive register content information from another guest by leveraging pending exception and mask bits. NOTE: this vulnerability exists because of an incorrect fix for CVE-2013-2076.

Frequently asked questions

What is CVE-2016-3158?: The xrstor function in arch/x86/xstate.c in Xen 4.x does not properly handle writes to the hardware FSW.ES bit when running on AMD64 processors, which allows local guest OS users to obtain sensitive register content information from another guest by leveraging pending exception and mask bits. NOTE: this vulnerability exists because of an incorrect fix for CVE-2013-2076.
How severe is CVE-2016-3158?: CVE-2016-3158 has a CVSS 3.x base score of 3.8, rated low severity. It is exploitable over local access with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is low, integrity none, and availability none.
Is CVE-2016-3158 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (33rd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2016-3158?: CVE-2016-3158 primarily affects Xen. In total, 5 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2016-3158?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2016-3158 published?: CVE-2016-3158 was published on 2016-04-13 and last updated on 2026-06-17.

References

Affected products (5)

cpe:2.3:o:xen:xen:*:*:*:*:*:*:*:*
cpe:2.3:o:fedoraproject:fedora:22:*:*:*:*:*:*:*
cpe:2.3:o:fedoraproject:fedora:23:*:*:*:*:*:*:*
cpe:2.3:o:oracle:vm_server:3.3:*:*:*:*:*:*:*
cpe:2.3:o:oracle:vm_server:3.4:*:*:*:*:*:*:*

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