---
id: CVE-2026-75973
title: Improper Authentication vulnerability in Apache Tomcat
summary: >-
  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 applica…
severity: high
cvss: 7.3
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L'
cwe:
  - CWE-287
vendor: Apache Software Foundation
product: Apache Tomcat
affected:
  - apache_tomcat >= 11.0.0-M1 <= 11.0.25
  - apache_tomcat >= 10.1.0-M1 <= 10.1.59
  - apache_tomcat >= 9.0.0.M4 <= 9.0.121
  - apache_tomcat >= 8.5.0 <= 8.5.100
published: '2026-09-23'
updated: '2026-09-23'
sourceUpdated: '2026-09-23T19:19:14.230'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-75973'
references:
  - url: 'https://lists.apache.org/thread/njjcdkkzqyzx4n3ffc4ffjmyh5mpl1gr'
    label: security@apache.org
  - url: 'http://www.openwall.com/lists/oss-security/2026/09/23/20'
    label: af854a3a-2127-422b-91ae-364da2661108
tags:
  - nvd
  - cve.org
ssvc:
  exploitation: none
  automatable: 'yes'
  technicalImpact: partial
  timestamp: '2026-09-23T15:28:51.510257Z'
ingestedAt: '2026-09-23T11:22:32.917Z'
epss: 0.00238
epssPercentile: 0.13289
---

## Overview

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.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.