CVE-2026-42498

Apache Tomcat: WebSocket authentication header exposure

Published May 12, 2026 CVSS 3.1 · 7.3 High EPSS < 1% KEV · Not listed
Description
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.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

Source ID Title
Debian DLA Debian DLA DLA-4619-1 tomcat9 security update
Debian DSA Debian DSA DSA-6328-1 tomcat10 security update
Debian DSA Debian DSA DSA-6329-1 tomcat11 security update
Github GHSA Github GHSA GHSA-fv25-8xcx-gqjc Apache Tomcat - WebSocket authentication header exposure
Ubuntu USN Ubuntu USN USN-8417-1 Tomcat vulnerabilities
Ubuntu USN Ubuntu USN USN-8450-1 Tomcat vulnerabilities
History
Type Values Removed Values Added
First Time appeared Apache tomcat
CPEs cpe:2.3:a:apache:tomcat:*:*:*:*:*:*:*:*
Vendors & Products Apache tomcat
Type Values Removed Values Added
Metrics cvssV3_1

{'score': 7.3, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L'}

ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
First Time appeared Apache
Apache apache Tomcat
Vendors & Products Apache
Apache apache Tomcat
Type Values Removed Values Added
Description 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.
Title Apache Tomcat: WebSocket authentication header exposure
Weaknesses CWE-200
References
Weaknesses

Sources

Status
PUBLISHED
Assigner
apache
Published
Updated
May 13, 2026, 3:59 PM
Reserved
Apr 27, 2026, 10:13 PM
Status
Analyzed
Published
May 12, 2026, 4:16 PM
Modified
Oct 26, 2026, 6:10 PM