The xrstor function in arch/x86/xstate.c in Xen 4.x does not properly handle writes to…
Priority LOW 18CWE-200Published · Updated
Key facts
- Attack vector
- Local
- Privileges required
- Low
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Information disclosure, Security bypass
- Confidentiality · integrity · availability
- Low · None · None
- Fix status
- No fix listed
Attack profile from CVSS 3.0 · NVD. Fix status from CNA. Impact type from CWE-200 and CWE-284.
Summary
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.
Why it matters now
EPSS 0.0041 35th percentileScored 2026-11-07
Fix No fix listed No fixed version in the sources yet
SSVC decision points
Not available: CISA has not published SSVC decision points for this record.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| — | — | all versions | — | No fix listed | CNA |
- — Vendor— Affected all versions Fixed in — No fix listed CNA
CPE configurations NVD · 5
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:o:xen:xen:*:*:*:*:*:*:*:* | up to 4.4.0 | Vulnerable | Xen |
| cpe:2.3:o:fedoraproject:fedora:22:*:*:*:*:*:*:* | 22 | Vulnerable | Fedoraproject |
| cpe:2.3:o:fedoraproject:fedora:23:*:*:*:*:*:*:* | 23 | Vulnerable | Fedoraproject |
| cpe:2.3:o:oracle:vm_server:3.3:*:*:*:*:*:*:* | 3.3 | Vulnerable | Oracle |
| cpe:2.3:o:oracle:vm_server:3.4:*:*:*:*:*:*:* | 3.4 | Vulnerable | Oracle |
- cpe:2.3:o:xen:xen:*:*:*:*:*:*:*:* Versions up to 4.4.0 Vulnerable ·Xen
- cpe:2.3:o:fedoraproject:fedora:22:*:*:*:*:*:*:* Versions 22 Vulnerable ·Fedoraproject
- cpe:2.3:o:fedoraproject:fedora:23:*:*:*:*:*:*:* Versions 23 Vulnerable ·Fedoraproject
- cpe:2.3:o:oracle:vm_server:3.3:*:*:*:*:*:*:* Versions 3.3 Vulnerable ·Oracle
- cpe:2.3:o:oracle:vm_server:3.4:*:*:*:*:*:*:* Versions 3.4 Vulnerable ·Oracle
Remediation
No fixed version listed by the sources yet.
Vendor assessments
Red Hat
Red Hat rating: Moderate. Red Hat's page for this CVE →
Not affected: 1 product
- Red Hat Enterprise Linux 5
Timeline
- 2026-10-02 Threatist record created from CVE-2016-3158
- 2026-10-03 Alias added: GHSA-96jh-8f37-hfp8
References
Advisory 5
Sources
- CVE-2016-3158 · CVE Program
- CVE-2016-3158 · NVD
- FIRST EPSS
- GHSA-96jh-8f37-hfp8 · GitHub Advisory Database · CC BY 4.0
- CVE-2016-3158 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences