CVE-2026-34487

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Last Modified: UTC

Description

A flaw was found in Apache Tomcat. The cloud membership for clustering component was vulnerable to the insertion of sensitive information into log files. This vulnerability could lead to the exposure of the Kubernetes bearer token, which is a credential used for authentication within a Kubernetes cluster, potentially allowing unauthorized access to cluster resources.

Statement

Low impact. This vulnerability in Apache Tomcat affects the cloud membership for clustering component, potentially exposing Kubernetes bearer tokens in log files. Exploitation requires the cloud membership feature to be enabled and an attacker to have access to the system's log files. Red Hat Enterprise Linux versions are affected if running Apache Tomcat with this specific clustering configuration.

Mitigation

Disable the cloud membership for clustering feature in Apache Tomcat if it is not actively used. Additionally, ensure that access to Apache Tomcat log files is strictly controlled and limited to authorized personnel only to prevent unauthorized disclosure of sensitive information. If the cloud membership for clustering feature is disabled, a restart of the Apache Tomcat service may be required for the changes to take effect.

Additional information

Affected Packages and Issued Red Hat Security Errata

Unless explicitly stated as not affected, all previous versions of packages in any minor update stream of a product listed here should be assumed vulnerable, although may not have been subject to full analysis.

Products / Services Components State Errata
Red Hat Enterprise Linux 10 tomcat Fix deferred
Red Hat Enterprise Linux 10 tomcat9 Fixed RHSA-2026:36790
Red Hat Enterprise Linux 6 tomcat6 Out of support scope
Red Hat Enterprise Linux 7 tomcat Fix deferred
Red Hat Enterprise Linux 8 pki-deps:10.6/pki-servlet-engine Fix deferred
Red Hat Enterprise Linux 8 tomcat Fix deferred
Red Hat Enterprise Linux 9 pki-servlet-engine Fix deferred
Red Hat Enterprise Linux 9 tomcat Fix deferred
Red Hat JBoss Web Server 5 tomcat Under investigation
Red Hat JBoss Web Server 6.2 on RHEL 10 jws6-tomcat Fixed RHSA-2026:20405

Common Vulnerability Scoring System (CVSS) Score Details

Important note

CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authorities (CNA) source for its products and services (see Red Hat classifications ).

CVSS v3 Score Breakdown

Red Hat NVD cve.org
CVSS v3 Base Score 6.5 N/A 7.5
Attack Vector Local N/A Network
Attack Complexity Low N/A Low
Privileges Required Low N/A None
User Interaction None N/A None
Scope Changed N/A Unchanged
Confidentiality Impact High N/A High
Integrity Impact None N/A None
Availability Impact None N/A None

CVSS v3 Vector

Red Hat CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N

cve.org CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

Frequently Asked Questions

Why is Red Hat's CVSS v3 score or Impact different from other vendors?

For open source software shipped by multiple vendors, the CVSS base scores may vary for each vendor's version depending on the version they ship, how they ship it, the platform, and even how the software is compiled. This makes scoring of vulnerabilities difficult for third-party vulnerability databases such as NVD that only provide a single CVSS base score for each vulnerability. Red Hat scores reflect how a vulnerability affects our products specifically.

For more information, see https://access.redhat.com/solutions/762393.

My product is listed as "Under investigation" or "Affected", when will Red Hat release a fix for this vulnerability?

  • "Under investigation" doesn't necessarily mean that the product is affected by this vulnerability. It only means that our Analysis Team is still working on determining whether the product is affected and how it is affected.
  • "Affected" means that our Analysis Team has determined that this product is affected by this vulnerability and might release a fix to address this in the near future.

What can I do if my product is listed as "Will not fix"?

A "will not fix" status means that a fix for an affected product version is not planned or not possible due to complexity, which may create additional risk.

Available options depend mostly on the Impact of the vulnerability and the current Life Cycle phase of your product. Overall, you have the following options:
  • Upgrade to a supported product version that includes a fix for this vulnerability (recommended).
  • Apply a mitigation (if one exists).
  • Open a This content is not included.support case to request a prioritization of releasing a fix for this vulnerability.

What can I do if my product is listed as "Fix deferred"?

A deferred status means that a fix for an affected product version is not guaranteed due to higher-priority development work.

Available options depend mostly on the Impact of the vulnerability and the current Life Cycle phase of your product. Overall, you have the following options:
  • Apply a mitigation (if one exists).
  • Open a This content is not included.support case to request a prioritization of releasing a fix for this vulnerability.
  • Red Hat Engineering focuses on addressing high-priority issues based on their complexity or limited lifecycle support. Therefore, lower-priority issues will not receive immediate fixes.

What is a mitigation?

A mitigation is an action that can be taken to reduce the impact of a security vulnerability, without deploying any fixes.

I have a Red Hat product but it is not in the above list, is it affected?

The listed products were found to include one or more of the components that this vulnerability affects. These products underwent a thorough evaluation to determine their affectedness by this vulnerability. Note that layered products (such as container-based offerings) that consume affected components from any of the products listed in this table may be affected and are not represented.

Why is my security scanner reporting my product as vulnerable to this vulnerability even though my product version is fixed or not affected?

In order to maintain code stability and compatibility, Red Hat usually does not rebase packages to entirely new versions. Instead, we backport fixes and new features to an older version of the package we distribute. This can result in some security scanners that only consider the package version to report the package as vulnerable. To avoid this, we suggest that you use an approved vulnerability scanner from our This content is not included.Red Hat Vulnerability Scanner Certification program.

My product is listed as "Out of Support Scope". What does this mean?

When a product is listed as "Out of Support Scope", it means a vulnerability with the impact level assigned to this CVE is no longer covered by its current support lifecycle phase. The product has been identified to contain the impacted component, but analysis to determine whether it is affected or not by this vulnerability was not performed. The product should be assumed to be affected. Customers are advised to apply any mitigation options documented on this page, consider removing or disabling the impacted component, or upgrade to a supported version of the product that has an update available.