REDHAT-BUG-2476516: Medium severity Apache Tomcat vulnerability

Published May 12, 2026
·
Updated

Exposure of HTTP Authentication Header to unexpected hosts during WebSocket authentication vulnerability in Apache Tomcat.

This issue affects Apache Tomcat: from 11.0.0-M1 through 11.0.21, from 10.1.0-M1 through 10.1.54, from 9.0.2 through 9.0.117, from 8.5.24 through 8.5.100, from 7.0.83 through 7.0.109.

Users are recommended to upgrade to version 11.0.22, 10.1.55 or 9.0.118, which fix the issue.

Affected Software

5 affected components
Apache Tomcat>=11.0.0-M1<=11.0.21
Apache Tomcat>=10.1.0-M1<=10.1.54
Apache Tomcat>=9.0.2<=9.0.117
Apache Tomcat>=8.5.24<=8.5.100
Apache Tomcat>=7.0.83<=7.0.109

Remediation

Recommended actions to resolve this vulnerability, in priority order.

  1. Upgrade

    Upgrade Apache Tomcat to a version that resolves this vulnerability.

    Fixed in 11.0.22
  2. Upgrade

    Upgrade Apache Tomcat to a version that resolves this vulnerability.

    Fixed in 10.1.55
  3. Upgrade

    Upgrade Apache Tomcat to a version that resolves this vulnerability.

    Fixed in 9.0.118

Event History

May 12, 2026
Data Sourced
via Red Hat·04:02 PM
DescriptionSeverityAffected Software
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Frequently Asked Questions

1

What is the severity of REDHAT-BUG-2476516?

The severity of REDHAT-BUG-2476516 is classified as medium (4).

2

How does REDHAT-BUG-2476516 affect Apache Tomcat?

REDHAT-BUG-2476516 exposes the HTTP Authentication Header to unexpected hosts during WebSocket authentication in affected versions of Apache Tomcat.

3

Which versions of Apache Tomcat does REDHAT-BUG-2476516 impact?

REDHAT-BUG-2476516 affects Apache Tomcat versions from 11.0.0-M1 through 11.0.21, 10.1.0-M1 through 10.1.54, 9.0.2 through 9.0.117, 8.5.24 through 8.5.100, and 7.0.83 through the latest.

4

How do I fix REDHAT-BUG-2476516?

To fix REDHAT-BUG-2476516, upgrade your Apache Tomcat installation to a version that is not affected by this vulnerability.

5

What type of vulnerability is REDHAT-BUG-2476516?

REDHAT-BUG-2476516 is categorized as a WebSocket authentication vulnerability related to HTTP header exposure.

Contact

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