XSS in IBM I

CVE-2026-18099

IBM i 7.6, 7.5, 7.4, and 7.3 could allow a remote authenticated attacker to execute arbitrary script code due to improper neutralization of user-controlled input.

Vulnerability class: XSS (Cross-Site Scripting)

Published · last modified .

CVSS v3 metric

CVSS v3 base score 8.9 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:L.

EPSS exploit prediction

EPSS: 0.003 (23.1th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 23rd percentile — 23.1% 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-2026-18099: held from 0.002 to 0.003.

EPSS over last 30 days · oldest: 0.002 · newest: 0.003 · change: +0.001

Affected products

  • IBM I — versions 7.6, 7.5, 7.4

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-18099?
CVE-2026-18099 is a high-severity vulnerability in IBM I, classified under Cross-site Scripting. CVSS score: 8.9/10. Published 2026-08-12.
How severe is CVE-2026-18099?
High severity. CVSS v3 base score is 8.9 out of 10.