xen: x86 DB exception safety check can be triggered by a guest (XSA-265)
Published Jul 2, 2018
6.5
MEDIUMCVSS 3.0
EPSS 0.41%
Description
An issue was discovered in Xen through 4.10.x. One of the fixes in XSA-260 added some safety checks to help prevent Xen livelocking with debug exceptions. Unfortunately, due to an oversight, at least one of these safety checks can be triggered by a guest. A malicious PV guest can crash Xen, leading to a Denial of Service. All Xen systems which have applied the XSA-260 fix are vulnerable. Only x86 systems are vulnerable. ARM systems are not vulnerable. Only x86 PV guests can exploit the vulnerability. x86 HVM and PVH guests cannot exploit the vulnerability. An attacker needs to be able to control hardware debugging facilities to exploit the vulnerability, but such permissions are typically available to unprivileged users.
Affected products
No data.
Configuration 2
- 9.0
No data.
Red Hat Enterprise Linux 5
xen
Not affected
| Product | Package | State | Advisory |
|---|---|---|---|
| Red Hat Enterprise Linux 5 | xen | Not affected | 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:C/C:N/I:N/A:H
AV:L/AC:L/Au:N/C:N/I:N/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 2, 2026.
Score over time
2021–2026- EPSS v1
- EPSS v2
- EPSS v3
- EPSS v4
- EPSS v5
Percentile over time
- EPSS v1
- EPSS v2
- EPSS v3
- EPSS v4
- EPSS v5
Table of values (15 key points)
Flat stretches are collapsed; showing up to 120 newest points.
| Date | Score | Percentile | Model |
|---|---|---|---|
| Oct 2, 2026 | 0.41% (0.00414) | 33.45th | v5 (v2026.06.15) |
| Jun 15, 2026 | 0.41% (0.00414) | 32.84th | v5 (v2026.06.15) |
| Mar 17, 2025 | 0.08% (0.00077) | 20.55th | v4 (v2025.03.14) |
| Dec 12, 2024 | 0.06% (0.00062) | 28.60th | v3 (v2023.03.01) |
| Jun 20, 2024 | 0.06% (0.00062) | 26.75th | v3 (v2023.03.01) |
| Jun 26, 2023 | 0.06% (0.00062) | 24.73th | v3 (v2023.03.01) |
| Mar 7, 2023 | 0.04% (0.00045) | 12.26th | v3 (v2023.03.01) |
| Mar 6, 2023 | 1.28% (0.01282) | 68.34th | v2 (v2022.01.01) |
| Feb 22, 2023 | 1.28% (0.01282) | 68.05th | v2 (v2022.01.01) |
| Apr 1, 2022 | 1.28% (0.01282) | 65.91th | v2 (v2022.01.01) |
| Feb 4, 2022 | 1.28% (0.01282) | 41.72th | v2 (v2022.01.01) |
| Feb 3, 2022 | 2.57% (0.02567) | 55.02th | v1 |
| Jan 6, 2022 | 2.57% (0.02567) | 54.58th | v1 |
| Sep 1, 2021 | 2.57% (0.02567) | 78.88th | v1 |
| Apr 14, 2021 | 2.57% (0.02567) | 0.00th | v1 |
References (12)
- http://www.openwall.com/lists/oss-security/2018/06/27/11 mailing-listx_refsource_MLISTMailing ListMitigationPatchThird Party Advisory
- http://www.securityfocus.com/bid/104572 vdb-entryx_refsource_BIDThird Party AdvisoryVDB Entry
- http://www.securitytracker.com/id/1041202 vdb-entryx_refsource_SECTRACKThird Party AdvisoryVDB Entry
- http://xenbits.xen.org/xsa/advisory-265.html x_refsource_CONFIRMMitigationPatchVendor Advisory
- https://access.redhat.com/security/cve/CVE-2018-12893 Vendor Advisory
- https://bugzilla.redhat.com/show_bug.cgi?id=1590979 x_refsource_CONFIRMIssue TrackingMitigationThird Party Advisory
- https://lists.debian.org/debian-lts-announce/2018/11/msg00013.html mailing-listx_refsource_MLIST
- https://nvd.nist.gov/vuln/detail/CVE-2018-12893
- https://security.gentoo.org/glsa/201810-06 vendor-advisoryx_refsource_GENTOO
- https://support.citrix.com/article/CTX235748 x_refsource_CONFIRMVendor Advisory
- https://www.cve.org/CVERecord?id=CVE-2018-12893
- https://www.debian.org/security/2018/dsa-4236 vendor-advisoryx_refsource_DEBIANThird Party Advisory
Change history (0)
No recorded changes yet.