---
id: CVE-2026-78437
title: >-
  Incomplete cleanup vulnerability in Apache Tomcat allows a malformed request
  to potentially (depends on timing) cause one request from another user to
  fail.




  This issue affects Apache Tomcat: from 11.0.19 through 11.0.25, from 10.1.53 …
summary: >-
  Incomplete cleanup vulnerability in Apache Tomcat allows a malformed request
  to potentially (depends on timing) cause one request from another user to
  fail.




  This issue affects Apache Tomcat: from 11.0.19 through 11.0.25, from 10.1.53 …
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-459
vendor: Apache Software Foundation
product: Apache Tomcat
affected:
  - apache_tomcat >= 11.0.19 <= 11.0.25
  - apache_tomcat >= 10.1.53 <= 10.1.59
  - apache_tomcat >= 9.0.116 <= 9.0.121
published: '2026-09-23'
updated: '2026-09-23'
sourceUpdated: '2026-09-23T19:19:21.640'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-78437'
references:
  - url: 'https://lists.apache.org/thread/qkmsos3s8chn5053qr466rzwv6sk5gjg'
    label: security@apache.org
  - url: 'http://www.openwall.com/lists/oss-security/2026/09/23/26'
    label: af854a3a-2127-422b-91ae-364da2661108
tags:
  - nvd
  - cve.org
ssvc:
  exploitation: none
  automatable: 'yes'
  technicalImpact: partial
  timestamp: '2026-09-23T16:25:38.365317Z'
ingestedAt: '2026-09-23T12:24:04.184Z'
---

## Overview

Incomplete cleanup vulnerability in Apache Tomcat allows a malformed request to potentially (depends on timing) cause one request from another user to fail.



This issue affects Apache Tomcat: from 11.0.19 through 11.0.25, from 10.1.53 through 10.1.59, from 9.0.116 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.

## Remediation

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