What is CVE-2026-18838?

CVE-2026-18838 is a critical-severity vulnerability in IBM API Connect, classified under Authentication Bypass by Spoofing. CVSS score: 9.4/10. Published 2026-11-07.

How severe is CVE-2026-18838?

Critical severity. CVSS v3 base score is 9.4 out of 10.

Vulnerability in IBM API Connect

CVE-2026-18838

IBM API Connect 12.1.0.0 through 12.1.1.2 could allow a remote attacker to obtain sensitive information and modify API configurations due to improper authentication. Identity information supplied in requests is not sufficiently verified, which could allow a caller to impersonate another user.

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

CVSS v3 metric

CVSS v3 base score 9.4 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:L.

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-290 — Authentication Bypass by Spoofing

References

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

Frequently asked questions

What is CVE-2026-18838?: CVE-2026-18838 is a critical-severity vulnerability in IBM API Connect, classified under Authentication Bypass by Spoofing. CVSS score: 9.4/10. Published 2026-11-07.
How severe is CVE-2026-18838?: Critical severity. CVSS v3 base score is 9.4 out of 10.