Improper Authorization vulnerability when multiple method constraints define an HTTP method for the same extension 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. Users are recommended to upgrade to version 11.0.22, 10.1.55 or 9.0.118 which fix the issue.

The Linux/Unix host has one or more packages installed that are impacted by a vulnerability without a vendor supplied patch available.

  - Improper Authorization vulnerability when multiple method constraints define an HTTP method for the same     extension 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. Users are recommended to upgrade to version 11.0.22, 10.1.55 or 9.0.118 which fix the issue.
    (CVE-2026-43515)

Note that Nessus relies on the presence of the package as reported by the vendor.

The version of Tomcat installed on the remote host is prior to 10.1.55. It is, therefore, affected by multiple vulnerabilities as referenced in the fixed_in_apache_tomcat_10.1.55_security-10 advisory.

  - DEPRECATED: Authentication Bypass Issues vulnerability in digest authentication 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 before 7.0.0. Older unsupported versions any also be     affect Users are recommended to upgrade to version 11.0.22, 10.1.55 or 9.0.118 which fix the issue.
    (CVE-2026-43512)

  - Improper Authorization vulnerability when multiple method constraints define an HTTP method for the same     extension 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. Users are recommended to upgrade to version 11.0.22, 10.1.55 or 9.0.118 which fix the issue.
    (CVE-2026-43515)

  - Observable Timing Discrepancy vulnerability when comparing AJP secret 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.
    (CVE-2026-43514)

  - 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.
    (CVE-2026-43513)

  - 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. (CVE-2026-42498)

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

The version of Tomcat installed on the remote host is prior to 9.0.118. It is, therefore, affected by multiple vulnerabilities as referenced in the fixed_in_apache_tomcat_9.0.118_security-9 advisory.

  - DEPRECATED: Authentication Bypass Issues vulnerability in digest authentication 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 before 7.0.0. Older unsupported versions any also be     affect Users are recommended to upgrade to version 11.0.22, 10.1.55 or 9.0.118 which fix the issue.
    (CVE-2026-43512)

  - Improper Authorization vulnerability when multiple method constraints define an HTTP method for the same     extension 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. Users are recommended to upgrade to version 11.0.22, 10.1.55 or 9.0.118 which fix the issue.
    (CVE-2026-43515)

  - Observable Timing Discrepancy vulnerability when comparing AJP secret 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.
    (CVE-2026-43514)

  - 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.
    (CVE-2026-43513)

  - 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. (CVE-2026-42498)

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

ID	Name	Product	Family	Severity
314481	Linux Distros Unpatched Vulnerability : CVE-2026-43515	Nessus	Misc.	critical
314335	Apache Tomcat 10.1.0.M1 < 10.1.55 multiple vulnerabilities	Nessus	Web Servers	critical
314334	Apache Tomcat 9.0.0.M1 < 9.0.118 multiple vulnerabilities	Nessus	Web Servers	critical

Detections

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CVE-2026-43515

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Tenable Plugins

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