xen: x86 null segments not always treated as unusable (XSA-191)
Published Jan 23, 2017
7.8
HIGHCVSS 3.0
EPSS 0.45%
Description
The x86 emulator in Xen does not properly treat x86 NULL segments as unusable when accessing memory, which might allow local HVM guest users to gain privileges via vectors involving "unexpected" base/limit values.
Affected products
No data.
No data.
Red Hat Enterprise Linux 5
xen
Will not fix
| Product | Package | State | Advisory |
|---|---|---|---|
| Red Hat Enterprise Linux 5 | xen | Will not fix | n/a |
No package ranges for this CVE.
Remediation
No remediation recorded yet.
Metrics
No CVSS v4.0 score for this CVE.
No CVSS v3.1 score for this CVE.
CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
1 other source (Red Hat) ▾
CVSS:3.0/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
AV:L/AC:L/Au:N/C:P/I:P/A:P
This CVE is not in the KEV list.
No CISA SSVC assessment for this CVE yet.
Estimated probability of exploitation in the wild in the next 30 days (FIRST EPSS). As of Oct 1, 2026.
Score over time
2022–2026- EPSS v2
- EPSS v3
- EPSS v4
- EPSS v5
Percentile over time
- EPSS v2
- EPSS v3
- EPSS v4
- EPSS v5
Table of values (10 key points)
Flat stretches are collapsed; showing up to 120 newest points.
| Date | Score | Percentile | Model |
|---|---|---|---|
| Oct 1, 2026 | 0.45% (0.00450) | 36.77th | v5 (v2026.06.15) |
| Jun 15, 2026 | 0.45% (0.00450) | 35.55th | v5 (v2026.06.15) |
| Mar 17, 2025 | 0.10% (0.00100) | 25.37th | v4 (v2025.03.14) |
| Dec 12, 2024 | 0.06% (0.00062) | 28.60th | v3 (v2023.03.01) |
| Jun 13, 2024 | 0.06% (0.00062) | 26.61th | v3 (v2023.03.01) |
| Mar 7, 2023 | 0.06% (0.00062) | 24.59th | v3 (v2023.03.01) |
| Mar 6, 2023 | 0.95% (0.00950) | 32.28th | v2 (v2022.01.01) |
| Sep 10, 2022 | 0.95% (0.00950) | 30.63th | v2 (v2022.01.01) |
| Apr 1, 2022 | 0.95% (0.00950) | 28.61th | v2 (v2022.01.01) |
| Feb 4, 2022 | 0.95% (0.00950) | 13.46th | v2 (v2022.01.01) |
References (9)
- http://www.securityfocus.com/bid/94471 vdb-entryx_refsource_BIDThird Party AdvisoryVDB Entry
- http://www.securitytracker.com/id/1037340 vdb-entryx_refsource_SECTRACKThird Party AdvisoryVDB Entry
- http://xenbits.xen.org/xsa/advisory-191.html x_refsource_CONFIRMPatchVendor Advisory
- https://access.redhat.com/security/cve/CVE-2016-9386 Vendor Advisory
- https://bugzilla.redhat.com/show_bug.cgi?id=1392932 Issue Tracking
- https://nvd.nist.gov/vuln/detail/CVE-2016-9386
- https://security.gentoo.org/glsa/201612-56 vendor-advisoryx_refsource_GENTOO
- https://support.citrix.com/article/CTX218775 x_refsource_CONFIRMPatchThird Party Advisory
- https://www.cve.org/CVERecord?id=CVE-2016-9386
| Link | Providers | Tags |
|---|---|---|
| http://www.securityfocus.com/bid/94471 | vdb-entryx_refsource_BIDThird Party AdvisoryVDB Entry | |
| http://www.securitytracker.com/id/1037340 | vdb-entryx_refsource_SECTRACKThird Party AdvisoryVDB Entry | |
| http://xenbits.xen.org/xsa/advisory-191.html | x_refsource_CONFIRMPatchVendor Advisory | |
| https://access.redhat.com/security/cve/CVE-2016-9386 | Vendor Advisory | |
| https://bugzilla.redhat.com/show_bug.cgi?id=1392932 | Issue Tracking | |
| https://nvd.nist.gov/vuln/detail/CVE-2016-9386 | ||
| https://security.gentoo.org/glsa/201612-56 | vendor-advisoryx_refsource_GENTOO | |
| https://support.citrix.com/article/CTX218775 | x_refsource_CONFIRMPatchThird Party Advisory | |
| https://www.cve.org/CVERecord?id=CVE-2016-9386 |
Change history (0)
No recorded changes yet.