What is CVE-2026-16720?

CVE-2026-16720 is a critical-severity vulnerability in IBM API Connect, classified under Improper Authentication. CVSS score: 9.8/10. Published 2026-11-07.

How severe is CVE-2026-16720?

Critical severity. CVSS v3 base score is 9.8 out of 10.

Auth bypass in IBM API Connect

CVE-2026-16720

IBM API Connect 10.0.8.0 through 10.0.8.12 and 12.1.0.0 through 12.1.1.2 could allow a remote attacker to obtain valid access tokens for other users due to improper authentication. Authentication against a connected directory service is not sufficiently enforced, which could allow another user's identity to be assumed.

Vulnerability class: Broken Authentication

Published 2026-11-07 · last modified 2026-11-07.

CVSS v3 metric

CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

EPSS exploit prediction

No EPSS score from FIRST.org yet. New CVEs usually get one within a few days; no score means no signal yet, not low risk. How EPSS works.

Affected products

IBM API Connect

Weakness classification (CWE)

CWE-287 — Improper Authentication

References

www.ibm.com/support/pages/node/7295635 (vendor-advisory, patch)
www.ibm.com/support/pages/node/7295637 (vendor-advisory, patch)

Frequently asked questions

What is CVE-2026-16720?: CVE-2026-16720 is a critical-severity vulnerability in IBM API Connect, classified under Improper Authentication. CVSS score: 9.8/10. Published 2026-11-07.
How severe is CVE-2026-16720?: Critical severity. CVSS v3 base score is 9.8 out of 10.