Uncontrolled Resource Consumption vulnerability in Apache Tomcat's WebSocket chat example. This issue affects Apache Tomcat: from 11.0.0-M20 through 11.0.24, from 10.1.24 through 10.1.57, from 9.0.89 through 9.0.120. Users who have followed the security guidance to remove the examples web application are not affected by this issue. Users are recommended to remove the examples web application or to upgrade to version 11.0.25, 10.1.58 or 9.0.121 (when released), which fix the issue.

The version of tomcat installed on the remote host is prior to 9.0.121-1. It is, therefore, affected by a vulnerability as referenced in the ALAS2TOMCAT9-2026-028 advisory.

    Uncontrolled Resource Consumption vulnerability in Apache Tomcat's WebSocket chat example.

    This issue affects Apache Tomcat: from 11.0.0-M20 through 11.0.24, from 10.1.24 through 10.1.57, from     9.0.89 through 9.0.120. Users who have followed the security guidance to remove the examples web     application are not affected by this issue.

    Users are recommended to remove the examples web application or to upgrade to version 11.0.25, 10.1.58 or     9.0.121 (when released), which fix the issue. (CVE-2026-66299)

Tenable has extracted the preceding description block directly from the tested product security advisory.

Note that Nessus has not tested for this issue 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 10.1.59. It is, therefore, affected by multiple vulnerabilities as referenced in the fixed_in_apache_tomcat_10.1.59_security-10 advisory.

  - Uncontrolled Resource Consumption vulnerability in Apache Tomcat's WebSocket chat example. This issue     affects Apache Tomcat: from 11.0.0-M20 through 11.0.24, from 10.1.24 through 10.1.57, from 9.0.89 through     9.0.120. Users who have followed the security guidance to remove the examples web application are not     affected by this issue. Users are recommended to remove the examples web application or to upgrade to     version 11.0.25, 10.1.58 or 9.0.121 (when released), which fix the issue. (CVE-2026-66299)

  - Insufficient Session Expiration vulnerability in Apache Tomcat meant that if the session ID for an     authenticated HTTP session was changed after a WebSocket connection had been established under that     authenticated HTTP session, the WebSokcet session would not be closed as required by the Jakarta WebSocket     specification when the HTTP session ended. This issue affects Apache Tomcat: from 11.0.0-M1 through     11.0.24, from 10.1.0-M1 through 10.1.57, from 9.0.0.M1 through 9.0.120. The following versions were EOL at     the time the CVE was created but are known to be affected: from 8.5.0 through 8.5.100, from 7.0.43 through     7.0.109. Other unsupported versions may also be affected. Users are recommended to upgrade to version     11.0.25, 10.1.58 or 9.0.121, which fix the issue. (CVE-2026-73180)

  - Uncontrolled Resource Consumption vulnerability in Apache Tomcat via an allocation leak in the HTTP/2     backlog tracking when a stream is reset This issue affects Apache Tomcat: from 11.0.0-M1 through 11.0.24,     from 10.1.0-M1 through 10.1.57, from 9.0.39 through 9.0.120. The following versions were EOL at the time     the CVE was created but are known to be affected: from 8.5.59 through 8.5.100. Other unsupported versions     may also be affected. Users are recommended to upgrade to version 11.0.25, 10.1.58 or 9.0.121, which fix     the issue. (CVE-2026-68763)

  - Improper Authentication vulnerability in Apache Tomcat meant that in some circumstances (e.g. CLIENT-CERT,     SPNEGO) that a user would be authenticated even if the user did not exist in the DataSourceRealm. This     issue affects Apache Tomcat: from 11.0.0-M1 through 11.0.24, from 10.1.0-M1 through 10.1.57, from 9.0.0.M1     through 9.0.120. The following versions were EOL at the time the CVE was created but are known to be     affected: from 8.5.0 through 8.5.100, from 7.0.0 through 7.0.109. Other unsupported versions may also be     affected. Users are recommended to upgrade to version 11.0.25, 10.1.58 or 9.0.121, which fix the issue.
    (CVE-2026-68569)

  - Incorrect Authorization vulnerability in Apache Tomcat's FORM authentication process allows the bypassing     of a security constraint that limits user has access to a resource POST but not GET. This issue affects     Apache Tomcat: from 11.0.0-M1 through 11.0.24, from 10.1.0-M1 through 10.1.57, from 9.0.0.M1 through     9.0.120. The following versions were EOL at the time the CVE was created but are known to be affected:
    from 8.5.0 through 8.5.100, from 7.0.0 through 7.0.109. Other unsupported versions may also be affected.
    Users are recommended to upgrade to version 11.0.25, 10.1.58 or 9.0.121, which fixes the issue.
    (CVE-2026-68525)

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 Apache Tomcat installed on the remote host is prior to 9.0.121, 10.1.59, or 11.0.25. It is, therefore, affected by multiple vulnerabilities :

- The security constraint processing enabled a security constraint bypass if a constraint for a longer path was specified before a more restrictive constraint for a shorter sub-path. (CVE-2026-65182)

- A race condition (TOCTOU) when creating a Unix Domain Socket allowed an unauthorized local user to access the Unix Domain Socket. (CVE-2026-65183)

- An incomplete fix for CVE-2026-32990 allowed HTTP/2 no-authority requests to bypass strict SNI validation. (CVE-2026-65637)

- A limited replay attack was possible with DIGEST authentication if a client made an authenticated request with a nonceCount on the upper boundary of the replay window before windowSize requests had been made. (CVE-2026-65905)

- An off-by-one error in the RewriteValve [N] flag caused rewrite processing to restart at the second rule rather than the first, potentially allowing an attacker to bypass access control. (CVE-2026-65927)

- The WebSocket chat example provided an unbounded buffer for undelivered messages, allowing a maliciously slow client to cause memory exhaustion and failure of the Tomcat process. (CVE-2026-66299)

- security-role-ref definitions were incorrectly used as role aliases within the Realm, allowing servlet role references to bypass declarative role constraints. (CVE-2026-66422)

- The FORM authentication process allowed the bypassing of a security constraint that limited user access to a resource via POST but not GET. (CVE-2026-68525)

- For some authentication methods (e.g., CLIENT-CERT, SPNEGO), a user would be authenticated even if the user did not exist in the DataSourceRealm or JDBCRealm. (CVE-2026-68569)

- An allocation leak in HTTP/2 backlog tracking when a stream was reset could be manipulated to trigger a denial of service. (CVE-2026-68763)

- If the session ID for an authenticated HTTP session was changed after a WebSocket connection was established, the WebSocket session was not closed when the HTTP session ended as required by the Jakarta WebSocket specification. (CVE-2026-73180)

Note that the scanner has not attempted to exploit these issues but has instead relied only on the application's self-reported version number.

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

  - Uncontrolled Resource Consumption vulnerability in Apache Tomcat's WebSocket chat example. This issue     affects Apache Tomcat: from 11.0.0-M20 through 11.0.24, from 10.1.24 through 10.1.57, from 9.0.89 through     9.0.120. Users who have followed the security guidance to remove the examples web application are not     affected by this issue. Users are recommended to remove the examples web application or to upgrade to     version 11.0.25, 10.1.58 or 9.0.121 (when released), which fix the issue. (CVE-2026-66299)

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 9.0.121. It is, therefore, affected by multiple vulnerabilities as referenced in the fixed_in_apache_tomcat_9.0.121_security-9 advisory.

  - Uncontrolled Resource Consumption vulnerability in Apache Tomcat's WebSocket chat example. This issue     affects Apache Tomcat: from 11.0.0-M20 through 11.0.24, from 10.1.24 through 10.1.57, from 9.0.89 through     9.0.120. Users who have followed the security guidance to remove the examples web application are not     affected by this issue. Users are recommended to remove the examples web application or to upgrade to     version 11.0.25, 10.1.58 or 9.0.121 (when released), which fix the issue. (CVE-2026-66299)

  - Insufficient Session Expiration vulnerability in Apache Tomcat meant that if the session ID for an     authenticated HTTP session was changed after a WebSocket connection had been established under that     authenticated HTTP session, the WebSokcet session would not be closed as required by the Jakarta WebSocket     specification when the HTTP session ended. This issue affects Apache Tomcat: from 11.0.0-M1 through     11.0.24, from 10.1.0-M1 through 10.1.57, from 9.0.0.M1 through 9.0.120. The following versions were EOL at     the time the CVE was created but are known to be affected: from 8.5.0 through 8.5.100, from 7.0.43 through     7.0.109. Other unsupported versions may also be affected. Users are recommended to upgrade to version     11.0.25, 10.1.58 or 9.0.121, which fix the issue. (CVE-2026-73180)

  - Uncontrolled Resource Consumption vulnerability in Apache Tomcat via an allocation leak in the HTTP/2     backlog tracking when a stream is reset This issue affects Apache Tomcat: from 11.0.0-M1 through 11.0.24,     from 10.1.0-M1 through 10.1.57, from 9.0.39 through 9.0.120. The following versions were EOL at the time     the CVE was created but are known to be affected: from 8.5.59 through 8.5.100. Other unsupported versions     may also be affected. Users are recommended to upgrade to version 11.0.25, 10.1.58 or 9.0.121, which fix     the issue. (CVE-2026-68763)

  - Improper Authentication vulnerability in Apache Tomcat meant that in some circumstances (e.g. CLIENT-CERT,     SPNEGO) that a user would be authenticated even if the user did not exist in the DataSourceRealm. This     issue affects Apache Tomcat: from 11.0.0-M1 through 11.0.24, from 10.1.0-M1 through 10.1.57, from 9.0.0.M1     through 9.0.120. The following versions were EOL at the time the CVE was created but are known to be     affected: from 8.5.0 through 8.5.100, from 7.0.0 through 7.0.109. Other unsupported versions may also be     affected. Users are recommended to upgrade to version 11.0.25, 10.1.58 or 9.0.121, which fix the issue.
    (CVE-2026-68569)

  - Incorrect Authorization vulnerability in Apache Tomcat's FORM authentication process allows the bypassing     of a security constraint that limits user has access to a resource POST but not GET. This issue affects     Apache Tomcat: from 11.0.0-M1 through 11.0.24, from 10.1.0-M1 through 10.1.57, from 9.0.0.M1 through     9.0.120. The following versions were EOL at the time the CVE was created but are known to be affected:
    from 8.5.0 through 8.5.100, from 7.0.0 through 7.0.109. Other unsupported versions may also be affected.
    Users are recommended to upgrade to version 11.0.25, 10.1.58 or 9.0.121, which fixes the issue.
    (CVE-2026-68525)

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 11.0.25. It is, therefore, affected by multiple vulnerabilities as referenced in the fixed_in_apache_tomcat_11.0.25_security-11 advisory.

  - Uncontrolled Resource Consumption vulnerability in Apache Tomcat's WebSocket chat example. This issue     affects Apache Tomcat: from 11.0.0-M20 through 11.0.24, from 10.1.24 through 10.1.57, from 9.0.89 through     9.0.120. Users who have followed the security guidance to remove the examples web application are not     affected by this issue. Users are recommended to remove the examples web application or to upgrade to     version 11.0.25, 10.1.58 or 9.0.121 (when released), which fix the issue. (CVE-2026-66299)

  - Insufficient Session Expiration vulnerability in Apache Tomcat meant that if the session ID for an     authenticated HTTP session was changed after a WebSocket connection had been established under that     authenticated HTTP session, the WebSokcet session would not be closed as required by the Jakarta WebSocket     specification when the HTTP session ended. This issue affects Apache Tomcat: from 11.0.0-M1 through     11.0.24, from 10.1.0-M1 through 10.1.57, from 9.0.0.M1 through 9.0.120. The following versions were EOL at     the time the CVE was created but are known to be affected: from 8.5.0 through 8.5.100, from 7.0.43 through     7.0.109. Other unsupported versions may also be affected. Users are recommended to upgrade to version     11.0.25, 10.1.58 or 9.0.121, which fix the issue. (CVE-2026-73180)

  - Uncontrolled Resource Consumption vulnerability in Apache Tomcat via an allocation leak in the HTTP/2     backlog tracking when a stream is reset This issue affects Apache Tomcat: from 11.0.0-M1 through 11.0.24,     from 10.1.0-M1 through 10.1.57, from 9.0.39 through 9.0.120. The following versions were EOL at the time     the CVE was created but are known to be affected: from 8.5.59 through 8.5.100. Other unsupported versions     may also be affected. Users are recommended to upgrade to version 11.0.25, 10.1.58 or 9.0.121, which fix     the issue. (CVE-2026-68763)

  - Improper Authentication vulnerability in Apache Tomcat meant that in some circumstances (e.g. CLIENT-CERT,     SPNEGO) that a user would be authenticated even if the user did not exist in the DataSourceRealm. This     issue affects Apache Tomcat: from 11.0.0-M1 through 11.0.24, from 10.1.0-M1 through 10.1.57, from 9.0.0.M1     through 9.0.120. The following versions were EOL at the time the CVE was created but are known to be     affected: from 8.5.0 through 8.5.100, from 7.0.0 through 7.0.109. Other unsupported versions may also be     affected. Users are recommended to upgrade to version 11.0.25, 10.1.58 or 9.0.121, which fix the issue.
    (CVE-2026-68569)

  - Incorrect Authorization vulnerability in Apache Tomcat's FORM authentication process allows the bypassing     of a security constraint that limits user has access to a resource POST but not GET. This issue affects     Apache Tomcat: from 11.0.0-M1 through 11.0.24, from 10.1.0-M1 through 10.1.57, from 9.0.0.M1 through     9.0.120. The following versions were EOL at the time the CVE was created but are known to be affected:
    from 8.5.0 through 8.5.100, from 7.0.0 through 7.0.109. Other unsupported versions may also be affected.
    Users are recommended to upgrade to version 11.0.25, 10.1.58 or 9.0.121, which fixes the issue.
    (CVE-2026-68525)

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 10.1.58. It is, therefore, affected by a vulnerability as referenced in the fixed_in_apache_tomcat_10.1.58_security-10 advisory.

  - Uncontrolled Resource Consumption vulnerability in Apache Tomcat's WebSocket chat example. This issue     affects Apache Tomcat: from 11.0.0-M20 through 11.0.24, from 10.1.24 through 10.1.57, from 9.0.89 through     9.0.120. Users who have followed the security guidance to remove the examples web application are not     affected by this issue. Users are recommended to remove the examples web application or to upgrade to     version 11.0.25, 10.1.58 or 9.0.121 (when released), which fix the issue. (CVE-2026-66299)

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

ID	Name	Product	Family	Type	Severity
341910	Amazon Linux 2 : tomcat, --advisory ALAS2TOMCAT9-2026-028 (ALASTOMCAT9-2026-028)	Nessus	Amazon Linux Local Security Checks	Local	medium
339371	Apache Tomcat 10.1.0.M1 < 10.1.59 multiple vulnerabilities	Nessus	Web Servers	Combined	medium
115351	Apache Tomcat 9.0.x < 9.0.121 Multiple Vulnerabilities	Web App Scanning	Component Vulnerability	Version Based	critical
115350	Apache Tomcat 10.1.x < 10.1.59 Multiple Vulnerabilities	Web App Scanning	Component Vulnerability	Version Based	critical
115349	Apache Tomcat 11.0.x < 11.0.25 Multiple Vulnerabilities	Web App Scanning	Component Vulnerability	Version Based	critical
330598	Linux Distros Unpatched Vulnerability : CVE-2026-66299	Nessus	Misc.	Local	medium
330442	Apache Tomcat 9.0.0.M1 < 9.0.121 multiple vulnerabilities	Nessus	Web Servers	Combined	medium
330425	Apache Tomcat 11.0.0.M1 < 11.0.25 multiple vulnerabilities	Nessus	Web Servers	Combined	medium
330424	Apache Tomcat 10.1.24 < 10.1.58	Nessus	Web Servers	Combined	medium

Detections

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CVE-2026-66299

medium

Tenable Plugins

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critical

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critical

medium

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medium

medium