What is CVE-2026-34487?

CVE-2026-34487 is a high-severity vulnerability in Apache Tomcat, classified under Insertion of Sensitive Information into Log File. CVSS score: 7.5/10. Published 2026-04-09.

How severe is CVE-2026-34487?

High severity. CVSS v3 base score is 7.5 out of 10.

Information disclosure in Apache Tomcat

CVE-2026-34487

Insertion of Sensitive Information into Log File vulnerability in the cloud membership for clustering component of Apache Tomcat exposed the Kubernetes bearer token. This issue affects Apache Tomcat: from 11.0.0-M1 through 11.0.20, from 10.1.0-M1 through 10.1.53, from 9.0.13 through 9.0.116. Users are recommended to upgrade to version 11.0.21, 10.1.54 or 9.0.117, which fix the issue.

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

CVSS v3 metric

CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N.

EPSS exploit prediction

EPSS: 0.006 (47.7th percentile), scored 2026-09-29.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 48th percentile — 47.7% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.004 · newest: 0.006 · change: +0.002

Affected products

Apache Tomcat
Apache Software Foundation Tomcat — versions 11.0.0-M1, 10.1.0-M1, 9.0.13

Weakness classification (CWE)

CWE-532 — Insertion of Sensitive Information into Log File

References

lists.apache.org/thread/4xpkwolpkrj8v5xzp5nyovtlqp3y850h (vendor-advisory, Mailing List, Vendor Advisory)
af854a3a-2127-422b-91ae-364da2661108 (Mailing List, Third Party Advisory)

Frequently asked questions

What is CVE-2026-34487?: CVE-2026-34487 is a high-severity vulnerability in Apache Tomcat, classified under Insertion of Sensitive Information into Log File. CVSS score: 7.5/10. Published 2026-04-09.
How severe is CVE-2026-34487?: High severity. CVSS v3 base score is 7.5 out of 10.