Apache Tomcat 11.0.0.M1 < 11.0.26 multiple vulnerabilities

critical Nessus Plugin ID 349471

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Synopsis

The remote Apache Tomcat server is affected by multiple vulnerabilities

Description

The version of Tomcat installed on the remote host is prior to 11.0.26. It is, therefore, affected by multiple vulnerabilities as referenced in the fixed_in_apache_tomcat_11.0.26_security-11 advisory.

- CLIENT_CERT authentication does not fail as expected for some scenarios when soft fail is disabled vulnerability in Apache Tomcat. This issue affects Apache Tomcat: from 11.0.0-M14 through 11.0.25, from 10.1.22 through 10.1.59, from 9.0.92 through 9.0.121. Users are recommended to upgrade to version 11.0.26, 10.1.60 or 9.0.122, which fix the issue. (CVE-2026-86248)

- Allocation of resources without limits or throttling vulnerability in Apache Tomcat allows an unauthenticated AJP request to pin an AJP processing thread leading to denial of service. This issue affects Apache Tomcat: from 11.0.0-M1 through 11.0.25, from 10.1.0-M1 through 10.1.59, from 9.0.0.M1 through 9.0.121. 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 11.0.26, 10.1.60 or 9.0.122, which fix the issue.
(CVE-2026-78383)

- Improper Check for Certificate Revocation vulnerability in Apache Tomcat. Both the OpenSSL and OpenSSL-FFM TLS implementations ignore CRLs when certificate uses a keystore. This issue affects Apache Tomcat: from 11.0.0-M1 through 11.0.25, from 10.1.0-M1 through 10.1.58, from 9.0.0-M1 through 9.0.121. 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. Other unsupported versions may also be affected. Users are recommended to upgrade to version 11.0.26, 10.1.59, 9.0.122, which fixes the issue. (CVE-2026-73581)

- Improper Authentication vulnerability in Apache Tomcat. When Jakarta Authentication was configured with SimpleAuthConfigProvider as the default provider and multiple web application used that provider, the realm for the first web application to authenticate a request would be used for all web applications. This issue affects Apache Tomcat: from 11.0.0-M1 through 11.0.25, from 10.1.0-M1 through 10.1.59, from 9.0.0.M4 through 9.0.121. 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. Other unsupported versions may also be affected. Users are recommended to upgrade to version 11.0.26, 10.1.60, 9.0.122, which fixes the issue. (CVE-2026-75973)

- Authentication Bypass by Alternate Name vulnerability in Apache Tomcat allowed the security constraints for any WebSocket endpoint to be bypassed. This issue affects Apache Tomcat: from 11.0.0-M1 through 11.0.25, from 10.1.0-M1 through 10.1.59, from 9.0.0.M1 through 9.0.121. The following versions were EOS 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 11.0.26, 10.1.60 or 9.0.122, which fix the issue. (CVE-2026-76183)

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

Solution

Upgrade to Apache Tomcat version 11.0.26 or later.

Plugin Details

Severity: Critical

ID: 349471

File Name: tomcat_11_0_26.nasl

Version: 1.1

Type: Combined

Agent: windows, macosx, unix

Family: Web Servers

Published: 9/23/2026

Updated: 9/23/2026

Supported Sensors: Frictionless Assessment Agent, Nessus Agent, Tenable Cloud Security, Tenable Self-Hosted Container Security, Nessus

Risk Information

VPR

Risk Factor: Medium

Score: 4.9

Percentile: 58.29

CVSS v2

Risk Factor: Medium

Base Score: 5

Temporal Score: 3.7

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

CVSS Score Source: CVE-2026-78383

CVSS v3

Risk Factor: Critical

Base Score: 9.8

Temporal Score: 8.5

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

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

CVSS Score Source: CVE-2026-86248

Vulnerability Information

CPE: cpe:/a:apache:tomcat:11

Required KB Items: installed_sw/Apache Tomcat

Exploit Ease: No known exploits are available

Patch Publication Date: 9/15/2026

Vulnerability Publication Date: 9/15/2026

Reference Information

CVE: CVE-2026-73581, CVE-2026-75973, CVE-2026-76183, CVE-2026-77756, CVE-2026-77762, CVE-2026-77791, CVE-2026-78383, CVE-2026-78437, CVE-2026-79677, CVE-2026-86248, CVE-2026-86350, CVE-2026-87022

Detections

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