What is CVE-2018-19963?

CVE-2018-19963 is a high-severity vulnerability in Xen, classified under Reachable Assertion. CVSS score: 7.8/10. Published 2018-12-08.

How severe is CVE-2018-19963?

High severity. CVSS v3 base score is 7.8 out of 10.

Vulnerability in Xen

CVE-2018-19963

An issue was discovered in Xen 4.11 allowing HVM guest OS users to cause a denial of service (host OS crash) or possibly gain host OS privileges because x86 IOREQ server resource accounting (for external emulators) was mishandled.

Published 2018-12-08 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 7.8 (High). Vector: CVSS:3.0/AV:L/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.004 (27.7th percentile), scored 2026-09-29.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 28th percentile — 27.7% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.004 · newest: 0.004 · change: 0.000

Affected products

Xen — versions 4.11.0

Weakness classification (CWE)

CWE-617 — Reachable Assertion

References

xenbits.xen.org/xsa/advisory-276.html (Patch, Third Party Advisory)
www.securityfocus.com/bid/106182 (VDB Entry, Third Party Advisory, vdb-entry)

Frequently asked questions

What is CVE-2018-19963?: CVE-2018-19963 is a high-severity vulnerability in Xen, classified under Reachable Assertion. CVSS score: 7.8/10. Published 2018-12-08.
How severe is CVE-2018-19963?: High severity. CVSS v3 base score is 7.8 out of 10.