Vulnerability-Lookup

CVE-2026-66299 (GCVE-0-2026-66299)

Vulnerability from cvelistv5 – Published: 2026-07-28 14:29 – Updated: 2026-07-28 17:40

Title

Apache Tomcat: DoS via WebSocket chat example

Summary

Uncontrolled Resource Consumption vulnerability in Apache Tomcat's WebSocket chat example. This issue affects Apache Tomcat: from 11.0.0-M20 through 11.0.24, from 10.1.24 through 10.1.57, from 9.0.89 through 9.0.120. Users who have followed the security guidance to remove the examples web application are not affected by this issue. Users are recommended to remove the examples web application or to upgrade to version 11.0.25, 10.1.58 or 9.0.121 (when released), which fix the issue.

Severity

7.5 (High)


                        
                          CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

SSVC

Exploitation: none Automatable: yes Technical Impact: partial

CISA Coordinator (v2.0.3)

CWE

CWE-400 - Uncontrolled Resource Consumption

Assigner

apache

References

2 references

URL	Tags
https://lists.apache.org/thread/8owczcc1o8qw1rxmg…	vendor-advisory
http://www.openwall.com/lists/oss-security/2026/0…

Impacted products

1 product

Vendor	Product	Version
Apache Software Foundation	Apache Tomcat	Affected: 11.0.0-M20 , ≤ 11.0.24 (semver) Affected: 10.1.24 , ≤ 10.1.57 (semver) Affected: 9.0.89 , ≤ 9.0.120 (semver) Unaffected: 0 , ≤ 8.5.100 (semver)

Credits

4ra1n, pyn3rd and unam4

Show details on NVD website

JSON

To clipboard

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GHSA-RPF9-HRJR-88FV

Vulnerability from github – Published: 2026-07-28 15:32 – Updated: 2026-07-28 18:33

Details

Uncontrolled Resource Consumption vulnerability in Apache Tomcat's WebSocket chat example.

This issue affects Apache Tomcat: from 11.0.0-M20 through 11.0.24, from 10.1.24 through 10.1.57, from 9.0.89 through 9.0.120. Users who have followed the security guidance to remove the examples web application are not affected by this issue.

Users are recommended to remove the examples web application or to upgrade to version 11.0.25, 10.1.58 or 9.0.121 (when released), which fix the issue.

Severity

7.5 (High)


                  
                    CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Show details on source website

JSON

To clipboard

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  "affected": [],
  "aliases": [
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  ],
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    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-07-28T15:17:50Z",
    "severity": "HIGH"
  },
  "details": "Uncontrolled Resource Consumption vulnerability in Apache Tomcat\u0027s WebSocket chat example.\n\nThis issue affects Apache Tomcat: from 11.0.0-M20 through 11.0.24, from 10.1.24 through 10.1.57, from 9.0.89 through 9.0.120. Users who have followed the security guidance to remove the examples web application are not affected by this issue.\n\nUsers are recommended to remove the examples web application or to upgrade to version 11.0.25, 10.1.58 or 9.0.121 (when released), which fix the issue.",
  "id": "GHSA-rpf9-hrjr-88fv",
  "modified": "2026-07-28T18:33:02Z",
  "published": "2026-07-28T15:32:18Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-66299"
    },
    {
      "type": "WEB",
      "url": "https://lists.apache.org/thread/8owczcc1o8qw1rxmg9gvfk4w2jnh4l5k"
    },
    {
      "type": "WEB",
      "url": "http://www.openwall.com/lists/oss-security/2026/07/28/25"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
      "type": "CVSS_V3"
    }
  ]
}

Sightings

Author	Source	Type	Date	Other

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

Detection rules are retrieved from Rulezet.

The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.

Action not permitted

CVE-2026-66299 (GCVE-0-2026-66299)

GHSA-RPF9-HRJR-88FV

Tags

Sightings

Nomenclature