What is CVE-2026-17202?

CVE-2026-17202 is a medium-severity vulnerability in IBM API Connect, classified under Observable Response Discrepancy. CVSS score: 5.3/10. Published 2026-11-07.

How severe is CVE-2026-17202?

Medium severity. CVSS v3 base score is 5.3 out of 10.

Vulnerability in IBM API Connect

CVE-2026-17202

IBM API Connect 12.1.0.0 through 12.1.1.2 could allow a remote attacker to enumerate usernames due to observable differences in response behavior.

Published 2026-11-07 · last modified 2026-11-08.

CVSS v3 metric

CVSS v3 base score 5.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N.

EPSS exploit prediction

EPSS: 0.004 (34.7th percentile), scored 2026-11-09.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 35th percentile — 34.7% 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-204 — Observable Response Discrepancy

References

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

Frequently asked questions

What is CVE-2026-17202?: CVE-2026-17202 is a medium-severity vulnerability in IBM API Connect, classified under Observable Response Discrepancy. CVSS score: 5.3/10. Published 2026-11-07.
How severe is CVE-2026-17202?: Medium severity. CVSS v3 base score is 5.3 out of 10.