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

Vulnerability from cvelistv5 – Published: 2026-07-28 14:29 – Updated: 2026-07-28 17:40
VLAI
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 · CISA-ADP (v2.0.3)
Decision recorded 2026-07-28 17:39 UTC
CWE
  • CWE-400 - Uncontrolled Resource Consumption
Assigner
apache CNA under the mitre root
CNA scorecard B 76/100 over 1236 records in the last 180 days details
References
Impacted products
Vendor Product Version CPE status
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)
guessed Create a notification for this product.
Credits
4ra1n, pyn3rd and unam4
Show details on NVD website
To clipboard 

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How durations are calculated

Following the VTEM framework (Black Hat USA 2015), time to patch starts when the vendor or a coordinator was informed, total time to patch at discovery, and disclosure to patch at public disclosure; vendor response time runs from the report to its acknowledgement. Time to exploit and time unpatched start at the earliest discovery or report, falling back to public disclosure. Unpatched time ends at the first recorded patch, or the calculation time when no patch is recorded. Exploitation to patch shows the interval between those two events; a published proof of concept is a public exploit, not exploitation.

Each result shows its source dates. A negative interval means the end event came first; when date-only inputs leave the order open, the result says so. Date-only inputs are approximate. The earliest evidence wins: KEV report dates and sightings are labelled as such. Records describing another vulnerability are listed but never calculated from, and a PoC alone does not establish exploitation. Missing patch evidence does not prove that no patch exists. Filters below change the event list only.

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