What is CVE-2018-1635?

CVE-2018-1635 is a medium-severity vulnerability in IBM Informix Dynamic Server, classified under Out-of-bounds Write. CVSS score: 6.7/10. Published 2019-08-20.

How severe is CVE-2018-1635?

Medium severity. CVSS v3 base score is 6.7 out of 10.

Buffer overflow in IBM Informix Dynamic Server

CVE-2018-1635

Stack-based buffer overflow in oninit in IBM Informix Dynamic Server Enterprise Edition 12.1 allows an authenticated user to execute predefined code with root privileges, such as escalating to a root shell. IBM X-Force ID: 144439.

Vulnerability class: Buffer Overflow

Published 2019-08-20 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 6.7 (Medium). Vector: CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.004 (38.2th percentile), scored 2026-10-31.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 38th percentile — 38.2% 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

IBM Informix Dynamic Server — versions 12.10
IBM Informix Dynamic Server Enterprise Edition — versions 12.1

Weakness classification (CWE)

CWE-787 — Out-of-bounds Write

References

www.ibm.com/support/docview.wss (Vendor Advisory)
exchange.xforce.ibmcloud.com/vulnerabilities/144439 (VDB Entry, vdb-entry, Vendor Advisory)
security.netapp.com/advisory/ntap-20190903-0002/ (Third Party Advisory)

Frequently asked questions

What is CVE-2018-1635?: CVE-2018-1635 is a medium-severity vulnerability in IBM Informix Dynamic Server, classified under Out-of-bounds Write. CVSS score: 6.7/10. Published 2019-08-20.
How severe is CVE-2018-1635?: Medium severity. CVSS v3 base score is 6.7 out of 10.