CVE-2026-78437

Description

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.

Overview

State: PUBLISHED
Assigner (CNA): apache
CVSS severity: —
CVSS score: —
CVSS vector: —
Effective score: 7.3 / 10 HIGH source: NVD
CWE(s): CWE-459
Reserved: 2026-08-24
Published: 2026-09-23 11:26 UTC
Last updated: 2026-09-23 18:10 UTC
Source: https://raw.githubusercontent.com/CVEProject/cvelistV5/main/cves/2026/78xxx/CVE-2026-78437.json

NVD triage scoring NVD CVE 2.0

Layer NVD adds on top of the CNA's CVE record — published / last-modified timestamps, exploitability / impact subscores, and the FIRST.org EPSS probability that this CVE will be exploited in the wild in the next 30 days.

NVD published: 2026-09-23 12:17:07 UTC
NVD last modified: 2026-09-23 19:19:21 UTC
NVD CVSS v3.1: 7.3 / 10 HIGH source: 134c704f-9b21-4f2e-91b3-4a467353bcc0
NVD CVSS vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L
Exploitability subscore: 3.9 / 10
Impact subscore: 3.4 / 10

European Union Vulnerability Database ENISA EUVD

ENISA's official EU repository for curated vulnerability intelligence. Carries a separate identifier (EUVD-YYYY-NNNN) and frequently exposes an earlier-published description + CVSS than NVD does.

EUVD ID: EUVD-2026-85231
Assigner: apache
Published: Sep 23, 2026, 11:26:29 AM
Updated: Sep 23, 2026, 6:10:46 PM
EUVD base score (CVSS 3.1): 7.3 / 10
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L
EUVD-reported EPSS: 0.0000
Vendors: Apache Software Foundation
Products: Apache Tomcat (10.1.53 ≤10.1.59)

Apache Tomcat (11.0.19 ≤11.0.25)

Apache Tomcat (9.0.116 ≤9.0.121)
Aliases: GHSA-hvg5-8g86-xm44

ENISA description: 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.

EUVD references (1)

https://lists.apache.org/thread/qkmsos3s8chn5053qr466rzwv6sk5gjg

Affected products (1)

Vendor	Product	Versions	Platforms
Apache Software Foundation	Apache Tomcat	`11.0.19` (affected), `10.1.53` (affected), `9.0.116` (affected), `0` (unaffected)	—

Vendor references (1)

References embedded in the original CVE record by the assigning CNA.

https://lists.apache.org/thread/qkmsos3s8chn5053qr466rzwv6sk5gjg vendor-advisory

Web references (0)

DuckDuckGo results ranked by threat-intel / vendor advisory domains. Generated by the 🔎 Find references (web) button above — same flow as the Remediations search.

No web references attached yet.

NVD-tagged references (2)

Reference list NVD curates from the CNA record, vendor advisories, and third-party reports. The tag chips below are NVD's analyst-assigned categories.

http://www.openwall.com/lists/oss-security/2026/09/23/26 af854a3a-2127-422b-91ae-364da2661108
https://lists.apache.org/thread/qkmsos3s8chn5053qr466rzwv6sk5gjg security@apache.org

Remediations (10)

CVE-2026-78437: Apache Tomcat Vulnerability | CVETodo

web:cvetodo.com

CVE-2026-78437 vulnerability details and analysis. Full technical analysis, mitigations , and exploit status — updated in real time.

2026-09-24 11:50 UTC
CVE-2026-78437 : Incomplete Cleanup Vulnerability in Apache Tomcat ...

web:securityvulnerability.io

What is CVE-2026-78437 ? An incomplete cleanup vulnerability exists in the Apache Tomcat application that could potentially lead to failures when processing requests under specific timing conditions.

2026-09-24 11:50 UTC
Microsoft Patch Tracker (September 2026): Exploit-Ranked | Senserva

web:senserva.com

Every Microsoft security patch (KB) and the CVEs it fixes, with severity, CVSS, and CISA KEV status. Cross-linked to the CVE reference.

2026-09-24 11:50 UTC
SAP Security Patch Day - June 2026

web:support.sap.com

SAP security Patch Day Bulletin This post shares the information on security notes that remediate vulnerabilities discovered in SAP products. SAP strongly recommends that the customer visits the support portal and applies patches on priority to protect their SAP landscape. On 9th of June 2026 , SAP security patch day saw the release of 15 new security notes.

2026-09-24 11:50 UTC
SAP Security Patch Day - May 2026

web:support.sap.com

SAP security Patch Day Bulletin This post shares the information on security notes that remediate vulnerabilities discovered in SAP products. SAP strongly recommends that the customer visits the support portal and applies patches on priority to protect their SAP landscape. On 12 th of May 2026 , SAP security patch day saw the release of 15 new security notes.

2026-09-24 11:50 UTC
CVE-2026-78437 - Incomplete Cleanup Vulnerability in Apache…

web:vulmon.com

Vulnerability Summary An incomplete cleanup vulnerability in Apache Tomcat may cause one user's request to fail, depending on timing. This issue affects Apache Tomcat versions 11.0.19 through 11.0.25, 10.1.53 through 10.1.59, and 9.0.116 through 9.0.121. Users should upgrade to version 11.0.26, 10.1.60, or 9.0.122.

2026-09-24 11:50 UTC
CVE-2026-78437 - vulnerability database | Vulners.com

web:vulners.com

CVE-2026-78437 🗓️ 23 Sep 2026 04:26:29 Reported by apache Type cve 🔗 web.nvd.nist.gov 👁 8 Views

2026-09-24 11:50 UTC
Oracle Critical Patch Update Advisory - July 2026

web:www.oracle.com

This Critical Patch Update contains 1448 new security patches across the product families listed below. Please note that a My Oracle Support (MOS) note summarizing the content of this Critical Patch Update and other Oracle Software Security Assurance activities is located at July 2026 Critical Patch Update: Executive Summary and Analysis.

2026-09-24 11:50 UTC
CVE-2026-78437: Apache Software Foundation Apache Tomcat ... - Rapid7

web:www.rapid7.com

CVE-2026-78437 : Apache Software Foundation Apache Tomcat: Incomplete cleanup vulnerability in Apache Tomcat allows a malformed request to potentially (depends on timing) cause…. View severity, references, and remediation details from Rapid7.

2026-09-24 11:50 UTC
CVE-2026-78437 | Tenable®

web:www.tenable.com

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.

2026-09-24 11:50 UTC

AI Forensic Analysis

Only Available for Registered Users. Sign in to view.

Raw JSON

The full cvelistV5 record. Download as CVE-2026-78437.json.

{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "cvssV3_1": {
              "attackComplexity": "LOW",
              "attackVector": "NETWORK",
              "availabilityImpact": "LOW",
              "baseScore": 7.3,
              "baseSeverity": "HIGH",
              "confidentialityImpact": "LOW",
              "integrityImpact": "LOW",
              "privilegesRequired": "NONE",
              "scope": "UNCHANGED",
              "userInteraction": "NONE",
              "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L",
              "version": "3.1"
            }
          },
          {
            "other": {
              "content": {
                "id": "CVE-2026-78437",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "yes"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-09-23T16:25:38.365317Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-09-23T16:25:54.815Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      },
      {
        "providerMetadata": {
          "dateUpdated": "2026-09-23T18:10:46.744Z",
          "orgId": "af854a3a-2127-422b-91ae-364da2661108",
          "shortName": "CVE"
        },
        "references": [
          {
            "url": "http://www.openwall.com/lists/oss-security/2026/09/23/26"
          }
        ],
        "title": "CVE Program Container"
      }
    ],
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Apache Tomcat",
          "vendor": "Apache Software Foundation",
          "versions": [
            {
              "lessThanOrEqual": "11.0.25",
              "status": "affected",
              "version": "11.0.19",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "10.1.59",
              "status": "affected",
              "version": "10.1.53",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "9.0.121",
              "status": "affected",
              "version": "9.0.116",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "8.5.100",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "supportingMedia": [
            {
              "base64": false,
              "type": "text/html",
              "value": "<p>Incomplete cleanup vulnerability in Apache Tomcat allows a malformed request to potentially (depends on timing) cause one request from another user to fail.</p><p>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.</p><p>Users are recommended to upgrade to version 11.0.26, 10.1.60 or 9.0.122, which fix the issue.</p>"
            }
          ],
          "value": "Incomplete cleanup vulnerability in Apache Tomcat allows a malformed request to potentially (depends on timing) cause one request from another user to fail.\n\n\n\nThis 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.\n\n\n\nUsers are recommended to upgrade to version 11.0.26, 10.1.60 or 9.0.122, which fix the issue."
        }
      ],
      "metrics": [
        {
          "other": {
            "content": {
              "text": "low"
            },
            "type": "Textual description of severity"
          },
          "scenarios": [
            {
              "lang": "en",
              "value": "GENERAL"
            }
          ]
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-459",
              "description": "CWE-459 Incomplete cleanup",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-09-23T11:26:29.362Z",
        "orgId": "f0158376-9dc2-43b6-827c-5f631a4d8d09",
        "shortName": "apache"
      },
      "references": [
        {
          "tags": [
            "vendor-advisory"
          ],
          "url": "https://lists.apache.org/thread/qkmsos3s8chn5053qr466rzwv6sk5gjg"
        }
      ],
      "source": {
        "discovery": "INTERNAL"
      },
      "title": "Apache Tomcat: HTTP/2 DoS via malformed request",
      "x_generator": {
        "engine": "Vulnogram 1.0.3"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "f0158376-9dc2-43b6-827c-5f631a4d8d09",
    "assignerShortName": "apache",
    "cveId": "CVE-2026-78437",
    "datePublished": "2026-09-23T11:26:29.362Z",
    "dateReserved": "2026-08-24T16:10:49.885Z",
    "dateUpdated": "2026-09-23T18:10:46.744Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}