CVE-2026-43513

Apache Tomcat: LockOutRealm treats user names as case-sensitive

Published May 12, 2026 CVSS 3.1 · 7.5 High EPSS < 1% KEV · Not listed
Description
Improper Handling of Case Sensitivity vulnerability in LockOutRealm 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 9.0.0.M1 through 9.0.117, from 8.5.0 through 8.5.100, from 7.0.0 through 7.0.109.
Older unsupported versions may also be affected.

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-5mp6-jrq3-r938 Apache Tomcat: LockOutRealm treats user names as case-sensitive
Ubuntu USN Ubuntu USN USN-8417-1 Tomcat vulnerabilities
Ubuntu USN Ubuntu USN USN-8383-1 Tomcat vulnerabilities
History
Type Values Removed Values Added
CPEs cpe:2.3:a:apache:tomcat:*:*:*:*:*:*:*:*
Type Values Removed Values Added
Metrics ssvc

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

Type Values Removed Values Added
Metrics cvssV3_1

{'score': 7.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N'}

Type Values Removed Values Added
First Time appeared Apache
Apache tomcat
Vendors & Products Apache
Apache tomcat
Type Values Removed Values Added
Description Improper Handling of Case Sensitivity vulnerability in LockOutRealm 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 9.0.0.M1 through 9.0.117, from 8.5.0 through 8.5.100, from 7.0.0 through 7.0.109. Older unsupported versions may also be affected. Users are recommended to upgrade to version 11.0.22, 10.1.55 or 9.0.118 which fix the issue.
Title Apache Tomcat: LockOutRealm treats user names as case-sensitive
Weaknesses CWE-178
References
Weaknesses

Sources

Status
PUBLISHED
Assigner
apache
Published
Updated
May 14, 2026, 7:53 PM
Reserved
May 1, 2026, 4:21 PM
Status
Analyzed
Published
May 12, 2026, 4:16 PM
Modified
Oct 26, 2026, 6:10 PM