What is CVE-2026-17158?

CVE-2026-17158 is a critical-severity vulnerability in IBM API Connect, classified under Improper Authentication. CVSS score: 9.9/10. Published 2026-11-07.

How severe is CVE-2026-17158?

Critical severity. CVSS v3 base score is 9.9 out of 10.

Auth bypass in IBM API Connect

CVE-2026-17158

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 authenticated attacker to gain elevated privileges due to improper authentication.

Vulnerability class: Broken Authentication

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

CVSS v3 metric

CVSS v3 base score 9.9 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.007 (51.9th percentile), scored 2026-11-09.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 52nd percentile — 51.9% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

The 30-day trend appears once there are two daily scores.

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-2026-17158?: CVE-2026-17158 is a critical-severity vulnerability in IBM API Connect, classified under Improper Authentication. CVSS score: 9.9/10. Published 2026-11-07.
How severe is CVE-2026-17158?: Critical severity. CVSS v3 base score is 9.9 out of 10.