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

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 astandard 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 . Several security issues in Tomcat found in Ubuntu 14.04 and 16.04 require immediate attention to maintain system integrity.. Ubuntu security, Tomcat updates, system vulnerabilities, authentication risks, Linux server management. . Severity: Critical. LinuxSecurity.com Team

Jun 05, 2026 •Critical Ubuntu