CVE-2026-43513
HIGH7.5EPSS 0.08%Apache Tomcat: LockOutRealm treats user names as case-sensitive
Published: 5/12/2026Modified: 5/19/2026
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.
Affected packages (7)
- Bitnami/tomcat>= 10.1.0, < 10.1.55, >= 11.0.0, < 11.0.22, >= 9.0.0, < 9.0.118
- Debian/tomcat10from 0
- Debian/tomcat11from 0
- Debian/tomcat9from 0, < 9.0.70-2
- Maven/org.apache.tomcat.embed:tomcat-embed-corefrom 0, < 9.0.118
- Maven/org.apache.tomcat:tomcatfrom 0, < 9.0.118
- Maven/org.apache.tomcat:tomcat-catalinafrom 0, < 9.0.118
CVSS scores
| Source | Version | Severity | Vector |
|---|---|---|---|
| osv | CVSS 3.1 | HIGH7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N |
References (11)
- ADVISORYhttps://nvd.nist.gov/vuln/detail/CVE-2026-43513
- ADVISORYhttps://security-tracker.debian.org/tracker/CVE-2026-43513
- PATCHhttps://github.com/apache/tomcat
- WEBhttps://github.com/apache/tomcat/commit/4a90d3fa93988c447cd5bb7482f76ff70d7f15c2
- WEBhttps://github.com/apache/tomcat/commit/6dd75beb55bd42fc5f78e929596b25018cd17717
- WEBhttps://github.com/apache/tomcat/commit/83f3e51df7b87f5f6e626951c575ded1a512e8ef
- WEBhttps://lists.apache.org/thread/ytjcgldshj73lcnd1sh95od5hrghwogp
- WEBhttps://tomcat.apache.org/security-10.html
- WEBhttps://tomcat.apache.org/security-11.html
- WEBhttps://tomcat.apache.org/security-9.html
- WEBhttp://www.openwall.com/lists/oss-security/2026/05/12/9