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Ubuntu 16.04 LTS Tomcat Critical Auth Bypass Issues USN-8383-1

Ubuntu Large Esm H500
Several security issues were fixed in Tomcat.
==========================================================================
Ubuntu Security Notice USN-8383-1
June 04, 2026

tomcat6, tomcat7 vulnerabilities
==========================================================================

A security issue affects these releases of Ubuntu and its derivatives:

- Ubuntu 16.04 LTS
- Ubuntu 14.04 LTS

Summary:

Several security issues were fixed in Tomcat.

Software Description:
- tomcat7: Servlet and JSP engine
- tomcat6: Servlet and JSP engine

Details:

It was discovered that Tomcat incorrectly handled digest
authentication. A remote attacker could possibly use this issue to
bypass authentication restrictions. (CVE-2026-43512)

It was discovered that Tomcat incorrectly handled case sensitivity
in LockOutRealm. A remote attacker could possibly use this issue to
bypass account lockout protections and obtain sensitive information.
(CVE-2026-43513)

It was discovered that Tomcat incorrectly handled authorization when
multiple method constraints defined the same HTTP method. A remote
attacker could possibly use this issue to bypass authorization
restrictions. (CVE-2026-43515)

Update instructions:

The problem can be corrected by updating your system to the following
package versions:

Ubuntu 16.04 LTS
  libtomcat7-java                 7.0.68-1ubuntu0.4+esm4
                                  Available with Ubuntu Pro
  tomcat7                         7.0.68-1ubuntu0.4+esm4
                                  Available with Ubuntu Pro

Ubuntu 14.04 LTS
  libtomcat6-java                 6.0.39-1ubuntu0.1+esm3
                                  Available with Ubuntu Pro
  libtomcat7-java                 7.0.52-1ubuntu0.16+esm2
                                  Available with Ubuntu Pro
  tomcat6                         6.0.39-1ubuntu0.1+esm3
                                  Available with Ubuntu Pro
  tomcat7                         7.0.52-1ubuntu0.16+esm2
                                  Available with Ubuntu Pro

After a standard system update you need to restart Tomcat to make
all the necessary changes.

References:
  https://ubuntu.com/security/notices/USN-8383-1
  CVE-2026-43512, CVE-2026-43513, CVE-2026-43515

Ubuntu 16.04 LTS Tomcat Critical Auth Bypass Issues USN-8383-1

ubuntu
Calendar Grey June 5, 2026
Dist Ubuntu Esm H88
Several security issues in Tomcat found in Ubuntu 14.04 and 16.04 require immediate attention to maintain system integrity.
Several security issues were fixed in Tomcat.

Summary

A security issue affects these releases of Ubuntu and its derivatives: - Ubuntu 16.04 LTS - Ubuntu 14.04 LTS Summary: Several security issues were fixed in Tomcat. Software Description: - tomcat7: Servlet and JSP engine - tomcat6: Servlet and JSP engine Details: It was discovered that Tomcat incorrectly handled digest authentication. A remote attacker could possibly use this issue to bypass authentication restrictions. (CVE-2026-43512) It was discovered that Tomcat incorrectly handled case sensitivity in LockOutRealm. A remote attacker could possibly use this issue to bypass account lockout protections and obtain sensitive information. (CVE-2026-43513) It was discovered that Tomcat incorrectly handled authorization when multiple method constraints defined the same HTTP method. A remote attacker could possibly use this issue to bypass authorization restrictions. (CVE-2026-43515)

Update Instructions

The problem can be corrected by updating your system to the following package versions: Ubuntu 16.04 LTS libtomcat7-java 7.0.68-1ubuntu0.4+esm4 Available with Ubuntu Pro tomcat7 7.0.68-1ubuntu0.4+esm4 Available with Ubuntu Pro Ubuntu 14.04 LTS libtomcat6-java 6.0.39-1ubuntu0.1+esm3 Available with Ubuntu Pro libtomcat7-java 7.0.52-1ubuntu0.16+esm2 Available with Ubuntu Pro tomcat6 6.0.39-1ubuntu0.1+esm3 Available with Ubuntu Pro tomcat7 7.0.52-1ubuntu0.16+esm2 Available with Ubuntu Pro After a standard system update you need to restart Tomcat to make all the necessary changes.

References

https://ubuntu.com/security/notices/USN-8383-1

CVE-2026-43512, CVE-2026-43513, CVE-2026-43515

Severity
critical
Lowest
Low
Medium
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Critical

Ubuntu Security Notice USN-8383-1

Package Information

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