CVE-2026-42498: Apache Tomcat: WebSocket authentication header exposure

Published May 12, 2026
·
Updated

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

Affected Software

10 affected componentsFixes available
Apache Tomcat>=11.0.0-M1<=11.0.21, >=10.1.0-M1<=10.1.54, >=9.0.2<=9.0.117, >=8.5.24<=8.5.100, >=7.0.83<=7.0.109
Apache Tomcat>=7.0.0<=7.0.109
Apache Tomcat>=8.5.0<=8.5.100
Apache Tomcat>=9.0.0<9.0.118
Apache Tomcat>=10.1.0<10.1.55
Apache Tomcat>=11.0.0<11.0.22
debian/tomcat10<=10.1.52-1~deb12u1, <=10.1.52-1~deb13u1
10.1.55-1~deb12u110.1.55-1~deb13u110.1.55-1
debian/tomcat11<=11.0.15-1~deb13u1
11.0.22-1~deb13u111.0.22-2
debian/tomcat9<=9.0.43-2~deb11u10
9.0.118-0+deb11u19.0.70-29.0.95-19.0.118-1
IBM API Connect V12 OnPrem<=All

Remediation

Recommended actions to resolve this vulnerability, in priority order.

  1. Upgrade

    Upgrade debian/tomcat10 to a version that resolves this vulnerability.

    Fixed in 10.1.55-1~deb12u1Fixed in 10.1.55-1~deb13u1Fixed in 10.1.55-1
  2. Upgrade

    Upgrade debian/tomcat11 to a version that resolves this vulnerability.

    Fixed in 11.0.22-1~deb13u1Fixed in 11.0.22-2
  3. Upgrade

    Upgrade debian/tomcat9 to a version that resolves this vulnerability.

    Fixed in 9.0.118-0+deb11u1Fixed in 9.0.70-2Fixed in 9.0.95-1Fixed in 9.0.118-1
  4. Upgrade

    Upgrade Apache Tomcat to a version that resolves this vulnerability.

    Fixed in 11.0.22
  5. Upgrade

    Upgrade Apache Tomcat to a version that resolves this vulnerability.

    Fixed in 10.1.55
  6. Upgrade

    Upgrade Apache Tomcat to a version that resolves this vulnerability.

    Fixed in 9.0.118

Event History

May 12, 2026
CVE Published
via MITRE·03:17 PM
Data Sourced
via MITRE·03:17 PM
DescriptionWeakness
Data Sourced
via Red Hat·04:02 PM
DescriptionSeverityAffected Software
Data Sourced
via NVD·04:16 PM
DescriptionSeverityWeaknessAffected Software
Jun 10, 2026
Data Sourced
via Launchpad·10:10 AM
Description
Jun 21, 2026
Data Sourced
via Ubuntu·05:49 PM
RemedyDescriptionSeverityAffected Software
Data Sourced
via Debian·05:50 PM
DescriptionAffected Software
Jul 7, 2026
Data Sourced
via IBM·12:00 AM
DescriptionAffected Software

Parent advisories

This vulnerability appears in the following advisories.

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Frequently Asked Questions

1

What is the severity of CVE-2026-42498?

The severity of CVE-2026-42498 is considered high due to the risk of exposing sensitive HTTP authentication headers.

2

How do I fix CVE-2026-42498?

To fix CVE-2026-42498, update Apache Tomcat to a version that is not affected, such as 11.0.22 or higher, 10.1.55 or higher, 9.0.118 or higher, 8.5.101 or higher, or 7.0.110 or higher.

3

What versions of Apache Tomcat are affected by CVE-2026-42498?

CVE-2026-42498 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 7.0.109.

4

What does CVE-2026-42498 expose?

CVE-2026-42498 exposes HTTP Authentication headers to unexpected hosts during WebSocket authentication.

5

Is there a workaround for CVE-2026-42498?

There are no documented workarounds for CVE-2026-42498; the recommended action is to upgrade to a fixed version.

Company

Resources

Contact

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