Missing Critical Step in Authentication vulnerability in Apache Tomcat when the JNDIRealm was configured to authenticate binds using GSSAPI allowed attackers to authenticate without provided the correct password. This issue affects Apache Tomcat: from 11.0.0-M1 through 11.0.4, from 10.1.0-M1 through 10.1.36, from 9.0.0.M1 through 9.0.100, from 8.5.0 through 8.5.100, from 7.0.0 through 7.0.109. Users are recommended to upgrade to version 11.0.5, 10.1.37 or 9.0.101, which fixes the issue.

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

  - Missing Critical Step in Authentication vulnerability in Apache Tomcat when the JNDIRealm was configured     to authenticate binds using GSSAPI allowed attackers to authenticate without provided the correct     password. This issue affects Apache Tomcat: from 11.0.0-M1 through 11.0.4, from 10.1.0-M1 through 10.1.36,     from 9.0.0.M1 through 9.0.100, from 8.5.0 through 8.5.100, from 7.0.0 through 7.0.109. Users are     recommended to upgrade to version 11.0.5, 10.1.37 or 9.0.101, which fixes the issue. (CVE-2026-55957)

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 9.0.102. It is, therefore, affected by a vulnerability as referenced in the fixed_in_apache_tomcat_9.0.102_security-9 advisory.

  - Missing Critical Step in Authentication vulnerability in Apache Tomcat when the JNDIRealm was configured     to authenticate binds using GSSAPI allowed attackers to authenticate without provided the correct     password. This issue affects Apache Tomcat: from 11.0.0-M1 through 11.0.4, from 10.1.0-M1 through 10.1.36,     from 9.0.0.M1 through 9.0.100, from 8.5.0 through 8.5.100, from 7.0.0 through 7.0.109. Users are     recommended to upgrade to version 11.0.5, 10.1.37 or 9.0.101, which fixes the issue. (CVE-2026-55957)

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 11.0.5. It is, therefore, affected by a vulnerability as referenced in the fixed_in_apache_tomcat_11.0.5_security-11 advisory.

  - Missing Critical Step in Authentication vulnerability in Apache Tomcat when the JNDIRealm was configured     to authenticate binds using GSSAPI allowed attackers to authenticate without provided the correct     password. This issue affects Apache Tomcat: from 11.0.0-M1 through 11.0.4, from 10.1.0-M1 through 10.1.36,     from 9.0.0.M1 through 9.0.100, from 8.5.0 through 8.5.100, from 7.0.0 through 7.0.109. Users are     recommended to upgrade to version 11.0.5, 10.1.37 or 9.0.101, which fixes the issue. (CVE-2026-55957)

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 10.1.39. It is, therefore, affected by a vulnerability as referenced in the fixed_in_apache_tomcat_10.1.39_security-10 advisory.

  - Missing Critical Step in Authentication vulnerability in Apache Tomcat when the JNDIRealm was configured     to authenticate binds using GSSAPI allowed attackers to authenticate without provided the correct     password. This issue affects Apache Tomcat: from 11.0.0-M1 through 11.0.4, from 10.1.0-M1 through 10.1.36,     from 9.0.0.M1 through 9.0.100, from 8.5.0 through 8.5.100, from 7.0.0 through 7.0.109. Users are     recommended to upgrade to version 11.0.5, 10.1.37 or 9.0.101, which fixes the issue. (CVE-2026-55957)

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

It is, therefore, affected by multiple vulnerabilities as referenced in the ALAS2023-2025-911 advisory.

    Path Equivalence: 'file.Name' (Internal Dot) leading to Remote Code Execution and/or Information     disclosure and/or malicious content added to uploaded files via write enabled Default Servlet in Apache     Tomcat.

    This issue affects Apache Tomcat: from 11.0.0-M1 through 11.0.2, from 10.1.0-M1 through 10.1.34, from     9.0.0.M1 through 9.0.98.

    If all of the following were true, a malicious user was able to view       security sensitive files and/or     inject content into those files:- writes enabled for the default servlet (disabled by default)- support     for partial PUT (enabled by default)- a target URL for security sensitive uploads that was a sub-directory     of a target URL for public uploads- attacker knowledge of the names of security sensitive files being     uploaded- the security sensitive files also being uploaded via partial PUT

    If all of the following were true, a malicious user was able to       perform remote code execution:-     writes enabled for the default servlet (disabled by default)- support for partial PUT (enabled by     default)- application was using Tomcat's file based session persistence with the default storage location-     application included a library that may be leveraged in a deserialization attack

    Users are recommended to upgrade to version 11.0.3, 10.1.35, 9.0.99 or later, which fixes the issue.

    More justification and the patch links are available for all versions here:[1]     https://tomcat.apache.org/security-11.html[2] https://tomcat.apache.org/security-10.html[3]     https://tomcat.apache.org/security-9.html (CVE-2025-24813)

    Missing Critical Step in Authentication vulnerability in Apache Tomcat when the JNDIRealm was configured     to authenticate binds using GSSAPI allowed attackers to authenticate without provided the correct     password.

    This issue affects Apache Tomcat: from 11.0.0-M1 through 11.0.4, from 10.1.0-M1 through 10.1.36, from     9.0.0.M1 through 9.0.100, from 8.5.0 through 8.5.100, from 7.0.0 through 7.0.109.

    Users are recommended to upgrade to version 11.0.5, 10.1.37 or 9.0.101, which fixes the issue.
    (CVE-2026-55957)

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

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 9.0.102-1. It is, therefore, affected by multiple vulnerabilities as referenced in the ALAS2TOMCAT9-2025-016 advisory.

    Path Equivalence: 'file.Name' (Internal Dot) leading to Remote Code Execution and/or Information     disclosure and/or malicious content added to uploaded files via write enabled Default Servlet in Apache     Tomcat.

    This issue affects Apache Tomcat: from 11.0.0-M1 through 11.0.2, from 10.1.0-M1 through 10.1.34, from     9.0.0.M1 through 9.0.98.

    If all of the following were true, a malicious user was able to view       security sensitive files and/or     inject content into those files:- writes enabled for the default servlet (disabled by default)- support     for partial PUT (enabled by default)- a target URL for security sensitive uploads that was a sub-directory     of a target URL for public uploads- attacker knowledge of the names of security sensitive files being     uploaded- the security sensitive files also being uploaded via partial PUT

    If all of the following were true, a malicious user was able to       perform remote code execution:-     writes enabled for the default servlet (disabled by default)- support for partial PUT (enabled by     default)- application was using Tomcat's file based session persistence with the default storage location-     application included a library that may be leveraged in a deserialization attack

    Users are recommended to upgrade to version 11.0.3, 10.1.35, 9.0.99 or later, which fixes the issue.

    More justification and the patch links are available for all versions here:[1]     https://tomcat.apache.org/security-11.html[2] https://tomcat.apache.org/security-10.html[3]     https://tomcat.apache.org/security-9.html (CVE-2025-24813)

    Missing Critical Step in Authentication vulnerability in Apache Tomcat when the JNDIRealm was configured     to authenticate binds using GSSAPI allowed attackers to authenticate without provided the correct     password.

    This issue affects Apache Tomcat: from 11.0.0-M1 through 11.0.4, from 10.1.0-M1 through 10.1.36, from     9.0.0.M1 through 9.0.100, from 8.5.0 through 8.5.100, from 7.0.0 through 7.0.109.

    Users are recommended to upgrade to version 11.0.5, 10.1.37 or 9.0.101, which fixes the issue.
    (CVE-2026-55957)

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

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

It is, therefore, affected by multiple vulnerabilities as referenced in the ALAS2023-2025-910 advisory.

    Path Equivalence: 'file.Name' (Internal Dot) leading to Remote Code Execution and/or Information     disclosure and/or malicious content added to uploaded files via write enabled Default Servlet in Apache     Tomcat.

    This issue affects Apache Tomcat: from 11.0.0-M1 through 11.0.2, from 10.1.0-M1 through 10.1.34, from     9.0.0.M1 through 9.0.98.

    If all of the following were true, a malicious user was able to view       security sensitive files and/or     inject content into those files:- writes enabled for the default servlet (disabled by default)- support     for partial PUT (enabled by default)- a target URL for security sensitive uploads that was a sub-directory     of a target URL for public uploads- attacker knowledge of the names of security sensitive files being     uploaded- the security sensitive files also being uploaded via partial PUT

    If all of the following were true, a malicious user was able to       perform remote code execution:-     writes enabled for the default servlet (disabled by default)- support for partial PUT (enabled by     default)- application was using Tomcat's file based session persistence with the default storage location-     application included a library that may be leveraged in a deserialization attack

    Users are recommended to upgrade to version 11.0.3, 10.1.35, 9.0.99 or later, which fixes the issue.

    More justification and the patch links are available for all versions here:[1]     https://tomcat.apache.org/security-11.html[2] https://tomcat.apache.org/security-10.html[3]     https://tomcat.apache.org/security-9.html (CVE-2025-24813)

    Missing Critical Step in Authentication vulnerability in Apache Tomcat when the JNDIRealm was configured     to authenticate binds using GSSAPI allowed attackers to authenticate without provided the correct     password.

    This issue affects Apache Tomcat: from 11.0.0-M1 through 11.0.4, from 10.1.0-M1 through 10.1.36, from     9.0.0.M1 through 9.0.100, from 8.5.0 through 8.5.100, from 7.0.0 through 7.0.109.

    Users are recommended to upgrade to version 11.0.5, 10.1.37 or 9.0.101, which fixes the issue.
    (CVE-2026-55957)

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

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
324690	Linux Distros Unpatched Vulnerability : CVE-2026-55957	Nessus	Misc.	high
323710	Apache Tomcat 9.0.0.M1 < 9.0.102	Nessus	Web Servers	high
323709	Apache Tomcat 11.0.0.M1 < 11.0.5	Nessus	Web Servers	high
323708	Apache Tomcat 10.1.0.M1 < 10.1.39	Nessus	Web Servers	high
233719	Amazon Linux 2023 : tomcat9, tomcat9-admin-webapps, tomcat9-el-3.0-api (ALAS2023-2025-911)	Nessus	Amazon Linux Local Security Checks	critical
233706	Amazon Linux 2 : tomcat, --advisory ALAS2TOMCAT9-2025-016 (ALASTOMCAT9-2025-016)	Nessus	Amazon Linux Local Security Checks	critical
233703	Amazon Linux 2023 : tomcat10, tomcat10-admin-webapps, tomcat10-el-5.0-api (ALAS2023-2025-910)	Nessus	Amazon Linux Local Security Checks	critical

Detections

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CVE-2026-55957

high

Tenable Plugins

high

high

high

high

critical

critical

critical