What is CVE-2026-34500?

CVE-2026-34500 is a medium-severity vulnerability in Apache Tomcat, classified under Improper Authentication. CVSS score: 6.5/10. Published 2026-04-09.

How severe is CVE-2026-34500?

Medium severity. CVSS v3 base score is 6.5 out of 10.

Auth bypass in Apache Tomcat

CVE-2026-34500

CLIENT_CERT authentication does not fail as expected for some scenarios when soft fail is disabled and FFM is used in Apache Tomcat. This issue affects Apache Tomcat: from 11.0.0-M14 through 11.0.20, from 10.1.22 through 10.1.53, from 9.0.92 through 9.0.116. Users are recommended to upgrade to version 11.0.21, 10.1.54 or 9.0.117, which fixes the issue.

Vulnerability class: Broken Authentication

Published 2026-04-09 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:L/A:N.

EPSS exploit prediction

EPSS: 0.004 (36.7th percentile), scored 2026-09-30.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 37th percentile — 36.7% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.005 · newest: 0.004 · change: -0.000

Affected products

Apache Tomcat — versions 11.0.0
Apache Software Foundation Tomcat — versions 11.0.0-M14, 10.1.22, 9.0.92

Weakness classification (CWE)

CWE-287 — Improper Authentication

References

lists.apache.org/thread/7rcl4zdxryc8hy3htyfyxkbqpxjtfdl2 (vendor-advisory, Vendor Advisory)
af854a3a-2127-422b-91ae-364da2661108 (Mailing List, Third Party Advisory)

Frequently asked questions

What is CVE-2026-34500?: CVE-2026-34500 is a medium-severity vulnerability in Apache Tomcat, classified under Improper Authentication. CVSS score: 6.5/10. Published 2026-04-09.
How severe is CVE-2026-34500?: Medium severity. CVSS v3 base score is 6.5 out of 10.