CVE-2018-19965 [Medium] | Denial of Service in Xen

An issue was discovered in Xen through 4.11.x allowing 64-bit PV guest OS users to cause a denial of service (host OS crash) because #GP[0] can occur after a non-canonical address is passed to the TLB flushing code. NOTE: this issue exists because of an incorrect CVE-2017-5754 (aka Meltdown) mitigation.

#	Date	Old EPSS score	New EPSS score	Delta (New - Old)
1	2025-11-21	0.13%	0.18%	+0.05%
2	2025-11-18	0.19%	0.13%	-0.06%
3	2025-08-20	—	0.19%	—

Date

Old EPSS score

New EPSS score

Delta (New - Old)

2025-11-21

0.13%

0.18%

+0.05%

2025-11-18

0.19%

0.13%

-0.06%

2025-08-20

—

0.19%

—

Base score	Version	Severity	Vector	Exploitability	Impact	Score source
5.6	3.0	MEDIUM	`CVSS:3.0/AV:L/AC:H/PR:L/UI:N/S:C/C:N/I:N/A:H` Click to expand Attack vector (AV:L) They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by. Attack complexity (AC:H) Even with access, the exploit needs extra luck, timing, or a fussy environment to actually work. Privileges required (PR:L) A normal user session is enough; they don’t have to be admin. User interaction (UI:N) Nobody has to click “OK” or open a trap file; it can work without a victim helping. Scope (S:C) Breaking this can reach past the original component and bite other resources—bigger blast radius. Confidentiality (C:N) Doesn’t really leak secrets in a meaningful way. Integrity (I:N) Data isn’t meaningfully altered or forged. Availability (A:H) Could take the service down hard or make it unusable for people who depend on it.	1.1	4.0	[email protected]
4.7	2.0	MEDIUM	`AV:L/AC:M/Au:N/C:N/I:N/A:C` Click to expand Access vector (AV:L) Requires local access to the target system. Access complexity (AC:M) Exploitation needs some favorable conditions, but not exceptional ones. Authentication (AU:N) No authentication is required. Confidentiality impact (C:N) No confidentiality impact. Integrity impact (I:N) No integrity impact. Availability impact (A:C) Complete availability impact.	3.4	6.9	[email protected]

Base score

Version

Severity

Vector

Exploitability

Impact

Score source

5.6

3.0

MEDIUM

CVSS:3.0/AV:L/AC:H/PR:L/UI:N/S:C/C:N/I:N/A:H Click to expand

Attack vector (AV:L): They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
Attack complexity (AC:H): Even with access, the exploit needs extra luck, timing, or a fussy environment to actually work.
Privileges required (PR:L): A normal user session is enough; they don’t have to be admin.
User interaction (UI:N): Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:C): Breaking this can reach past the original component and bite other resources—bigger blast radius.
Confidentiality (C:N): Doesn’t really leak secrets in a meaningful way.
Integrity (I:N): Data isn’t meaningfully altered or forged.
Availability (A:H): Could take the service down hard or make it unusable for people who depend on it.

1.1

4.0

[email protected]

4.7

2.0

MEDIUM

AV:L/AC:M/Au:N/C:N/I:N/A:C Click to expand

Access vector (AV:L): Requires local access to the target system.
Access complexity (AC:M): Exploitation needs some favorable conditions, but not exceptional ones.
Authentication (AU:N): No authentication is required.
Confidentiality impact (C:N): No confidentiality impact.
Integrity impact (I:N): No integrity impact.
Availability impact (A:C): Complete availability impact.

3.4

6.9

[email protected]

OS Trackers for CVE-2018-19965

vendor	priority	summary	link
`alpine`	medium	CVE-2018-19965: 1 source package rows (xen); 121 state rows across 10 repos (3.10-main, 3.11-main, 3.12-main, 3.17-main, 3.18-main, 3.19-main, 3.20-main, 3.21-main, 3.22-main, edge-main); fixed 10, open 111.	https://security.alpinelinux.org/vuln/CVE-2018-19965
`debian`	not yet assigned	CVE-2018-19965 not yet assigned priority: Debian including 1 source packages (xen), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5.	https://security-tracker.debian.org/tracker/CVE-2018-19965
`redhat`	high	—	https://access.redhat.com/security/cve/CVE-2018-19965
`ubuntu`	medium	CVE-2018-19965 medium priority: Ubuntu including 1 source packages (xen), 19 status rows across 19 suites (bionic, cosmic, disco, eoan, focal, groovy, hirsute, impish, jammy, kinetic, lunar, mantic, noble, oracular, plucky, questing, trusty, upstream, xenial): not-affected 9, ignored 6, needed 2, DNE 1, released 1.	https://ubuntu.com/security/CVE-2018-19965

Affected software / configurations for CVE-2018-19965

Vendor	Product	Version	Raw CPE
xen	xen	<= 4.11.1	cpe:2.3:o:xen:xen::::::::
citrix	xenserver	7.0	cpe:2.3:a:citrix:xenserver:7.0:::::::*
citrix	xenserver	7.1	cpe:2.3:a:citrix:xenserver:7.1:cu1:::ltsr:::*
citrix	xenserver	7.5	cpe:2.3:a:citrix:xenserver:7.5:::::::*
citrix	xenserver	7.6	cpe:2.3:a:citrix:xenserver:7.6:::::::*
debian	debian_linux	9.0	cpe:2.3:o:debian:debian_linux:9.0:::::::*

References for CVE-2018-19965

URL	Tags
http://lists.opensuse.org/opensuse-security-announce/2019-04/msg00072.html
http://www.securityfocus.com/bid/106182	Third Party Advisory VDB Entry
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/UXC6BME7SXJI2ZIATNXCAH7RGPI4UKTT/
https://support.citrix.com/article/CTX239432	Patch Third Party Advisory
https://www.debian.org/security/2019/dsa-4369	Third Party Advisory
https://xenbits.xen.org/xsa/advisory-279.html	Mitigation Patch Vendor Advisory

URL

CVE-2018-19965

Exploit prediction scoring system (EPSS) score for CVE-2018-19965

Common vulnerability scoring system (CVSS) metrics for CVE-2018-19965

Weakness enumeration for CVE-2018-19965

OS Trackers for CVE-2018-19965

Affected software / configurations for CVE-2018-19965

References for CVE-2018-19965