What is CVE-2026-18221?

CVE-2026-18221 is a high-severity vulnerability, classified under Improper Authentication. CVSS score: 8.1/10. Published 2026-09-04.

How severe is CVE-2026-18221?

High severity. CVSS v3 base score is 8.1 out of 10.

CVE-2026-18221

CVE-2026-18221

IBM i 7.6, 7.5, 7.4, and 7.3 could allow a remote attacker to gain unauthorized access due to improper validation of client-supplied authentication parameters.

Vulnerability class: Broken Authentication

CVSS v3 metric

CVSS v3 base score 8.1 (High). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H.

Weakness classification (CWE)

CWE-287 — Improper Authentication

References

psirt@us.ibm.com

Frequently asked questions

What is CVE-2026-18221?: CVE-2026-18221 is a high-severity vulnerability, classified under Improper Authentication. CVSS score: 8.1/10. Published 2026-09-04.
How severe is CVE-2026-18221?: High severity. CVSS v3 base score is 8.1 out of 10.