What is CVE-2018-18438?

CVE-2018-18438 is a medium-severity vulnerability in Qemu, classified under Integer Overflow or Wraparound. CVSS score: 5.5/10. Published 2018-10-19.

How severe is CVE-2018-18438?

Medium severity. CVSS v3 base score is 5.5 out of 10.

Integer overflow in Qemu

CVE-2018-18438

Qemu has integer overflows because IOReadHandler and its associated functions use a signed integer data type for a size value.

Vulnerability class: Integer Overflow

Published 2018-10-19 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 5.5 (Medium). Vector: CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H.

EPSS exploit prediction

EPSS: 0.004 (36.0th percentile), scored 2026-09-29.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 36th percentile — 36.0% 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

Qemu
Red Hat Enterprise Linux — versions 6.0, 7.0
Red Hat OpenStack — versions 8, 9, 10

Weakness classification (CWE)

CWE-190 — Integer Overflow or Wraparound

References

www.securityfocus.com/bid/105953 (VDB Entry, Third Party Advisory, vdb-entry)
lists.gnu.org/archive/html/qemu-devel/2018-10/msg02402.html (mailing-list, Patch, Mailing List, Third Party Advisory)
lists.gnu.org/archive/html/qemu-devel/2018-10/msg02396.html (mailing-list, Patch, Mailing List, Third Party Advisory)
www.openwall.com/lists/oss-security/2018/10/17/3 (mailing-list, Mailing List, Third Party Advisory)

Frequently asked questions

What is CVE-2018-18438?: CVE-2018-18438 is a medium-severity vulnerability in Qemu, classified under Integer Overflow or Wraparound. CVSS score: 5.5/10. Published 2018-10-19.
How severe is CVE-2018-18438?: Medium severity. CVSS v3 base score is 5.5 out of 10.