Buffer overflow in IBM I

CVE-2026-18086

IBM i 7.6, 7.5, 7.4, and 7.3 could allow a local attacker to execute arbitrary code or cause a denial of service due to improper bounds checking.

Vulnerability class: Buffer Overflow

Published · last modified .

CVSS v3 metric

CVSS v3 base score 4.5 (Medium). Vector: CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:L/I:L/A:L.

EPSS exploit prediction

EPSS: 0.001 (1.8th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 2nd percentile — 1.8% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-18086: held from 0.001 to 0.001.

EPSS over last 30 days · oldest: 0.001 · newest: 0.001 · change: +0.000

Affected products

  • IBM I — versions 7.6, 7.5, 7.4

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-18086?
CVE-2026-18086 is a medium-severity vulnerability in IBM I, classified under Out-of-bounds Write. CVSS score: 4.5/10. Published 2026-08-13.
How severe is CVE-2026-18086?
Medium severity. CVSS v3 base score is 4.5 out of 10.