Amazon Linux 2023 : tomcat9, tomcat9-admin-webapps, tomcat9-el-3.0-api (ALAS2023-2026-1945)

critical Nessus Plugin ID 328483

Synopsis

The remote Amazon Linux 2023 host is missing a security update.

Description

It is, therefore, affected by multiple vulnerabilities as referenced in the ALAS2023-2026-1945 advisory.

Improper Neutralization of Script-Related HTML Tags in a Web Page (Basic XSS) vulnerability in the number guess example for Apache Tomcat.

This issue affects Apache Tomcat: from 11.0.0-M1 through 11.0.22, from 10.1.0-M1 through 10.1.55, from 9.0.0.M1 through 9.0.118, from 8.5.0 through 8.5.100, from 7.0.0 through 7.0.109. Other versions that have reached end of support may also be affected.

Users are recommended to upgrade to version 11.0.23, 10.1.56 or 9.0.119, which fix the issue.
(CVE-2026-50229)

Always-Incorrect Control Flow Implementation vulnerability in Apache Tomcat's rewrite valve meant that if the first condition in an OR chain matched, subsequent non-OR conditions were skipped.

This issue affects Apache Tomcat: from 11.0.0-M1 through 11.0.22, from 10.1.0-M1 through 10.1.55, from 9.0.0.M1 through 9.0.118, from 8.5.0 through 8.5.100. Other versions that have reached end of support may also be affected.

Users are recommended to upgrade to version 11.0.23, 10.1.56 or 9.0.119, which fix the issue.
(CVE-2026-53404)

Detection of Error Condition Without Action vulnerability in Apache Tomcat when configuring CRLs for a FFM based connector.

This issue affects Apache Tomcat: from 11.0.0-M1 through 11.0.22, from 10.1.0-M7 through 10.1.55, from 9.0.83 through 9.0.118.

Users are recommended to upgrade to version 11.0.23, 10.1.56 or 9.0.119, which fixes the issue.
(CVE-2026-53434)

Always-Incorrect Control Flow Implementation vulnerability in Apache Tomcat meant that special roles and empty authorisation constraints were not included when the effective web.xml was logged.

This issue affects Apache Tomcat: from 11.0.0-M1 through 11.0.22, from 10.1.0-M1 through 10.1.55, from 9.0.0.M1 through 9.0.118, from 8.5.0 through 8.5.100. Other versions that have reached end of support may also be affected.

Users are recommended to upgrade to version 11.0.23, 10.1.56 or 9.0.119 which fixes the issue.
(CVE-2026-55276)

Improper Authentication vulnerability in Apache Tomcat allowed a replay attack against the EncryptionInterceptor in the cluster component.

This issue affects Apache Tomcat: from 11.0.0-M1 through 11.0.22, from 10.1.0-M1 through 10.1.55, from 9.0.13 through 9.0.18, from 8.5.38 through 8.5.100, from 7.0.100 through 7.0.109.

Users are recommended to upgrade to version 11.0.23, 10.1.56, 9.0.119, which fixes the issue.
(CVE-2026-55955)

Improper Authorization vulnerability in Apache Tomcat leads to security constraints specified for the default servlet ignoring any method or method omission configured as part of the constraint.

This issue affects Apache Tomcat: from 11.0.0-M1 through 11.0.22, from 10.1.0-M1 through 10.1.55, from 9.0.0.M1 through 9.0.118, from 8.5.0 through 8.5.100, from 7.0.0 through 7.0.109. Other versions that have reached end of support may also be affected.

Users are recommended to upgrade to version 11.0.23, 10.1.56 or 9.0.119, which fix the issue.
(CVE-2026-55956)

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.

Solution

Run 'dnf update tomcat9 --releasever 2023.12.20260720' or or 'dnf update --advisory ALAS2023-2026-1945 --releasever 2023.12.20260720' to update your system.

Plugin Details

Severity: Critical

ID: 328483

File Name: al2023_ALAS2023-2026-1945.nasl

Version: 1.1

Type: Local

Agent: unix

Family: Amazon Linux Local Security Checks

Published: 7/20/2026

Updated: 7/20/2026

Supported Sensors: Nessus Agent, Continuous Assessment, Nessus

Risk Information

VPR

Risk Factor: Medium

Score: 4.3

Percentile: 53.67

CVSS v2

Risk Factor: High

Base Score: 9.4

Temporal Score: 7.4

Vector: CVSS2#AV:N/AC:L/Au:N/C:C/I:C/A:N

CVSS Score Source: CVE-2026-55276

CVSS v3

Risk Factor: Critical

Base Score: 9.1

Temporal Score: 8.2

Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N

Temporal Vector: CVSS:3.0/E:P/RL:O/RC:C

Vulnerability Information

CPE: cpe:/o:amazon:linux:2023, p-cpe:/a:amazon:linux:tomcat9-admin-webapps, p-cpe:/a:amazon:linux:tomcat9-docs-webapp, p-cpe:/a:amazon:linux:tomcat9-el-3.0-api, p-cpe:/a:amazon:linux:tomcat9-jsp-2.3-api, p-cpe:/a:amazon:linux:tomcat9-lib, p-cpe:/a:amazon:linux:tomcat9-servlet-4.0-api, p-cpe:/a:amazon:linux:tomcat9-webapps, p-cpe:/a:amazon:linux:tomcat9

Required KB Items: Host/local_checks_enabled, Host/AmazonLinux/release, Host/AmazonLinux/rpm-list

Exploit Available: true

Exploit Ease: Exploits are available

Patch Publication Date: 7/20/2026

Vulnerability Publication Date: 6/22/2026

Reference Information

CVE: CVE-2026-50229, CVE-2026-53404, CVE-2026-53434, CVE-2026-55276, CVE-2026-55955, CVE-2026-55956

IAVA: 2026-A-0642

Detections

Analytics