CVE-2026-34487: Apache Tomcat: Cloud membership for clustering component exposed the Kubernetes bearer token

Severity: high (CVSS 7.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.4% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-04-09 · updated 2026-10-26
Weakness: CWE-532

Description

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.

Affected products

Apache Tomcat: from 9.0.13 before 9.0.117; from 10.1.0 before 10.1.54; from 11.0.0 before 11.0.21 — fixed in 9.0.117, 10.1.54, 11.0.21

How to fix

Upgrade to a fixed version: Apache Tomcat 9.0.117, 10.1.54, 11.0.21. Check the vendor advisory for mitigations.

References

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