SB20260728136 - Remote denial of service in Apache Tomcat
Published: July 28, 2026 Updated: August 25, 2026
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 1 vulnerability.
1) Allocation of Resources Without Limits or Throttling (CVE-ID: CVE-2026-66299)
CWE-ID: CWE-770 - Allocation of Resources Without Limits or Throttling
CVSSv4: 8.7 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]
The vulnerability allows a remote attacker to cause a denial of service.
The vulnerability exists due to improper resource management in the WebSocket chat example when buffering undelivered messages for a maliciously slow client connection. A remote attacker can maintain a slow client connection to cause a denial of service.
Only deployments exposing the example web application are vulnerable.
Remediation
Install update from vendor's website.
References
- https://tomcat.apache.org/security-11.html#Fixed_in_Apache_Tomcat_11.0.25
- https://github.com/apache/tomcat/commit/4e8e3f8964e9653bab427bf794e026c69ee80f2b
- https://tomcat.apache.org/security-10.html#Fixed_in_Apache_Tomcat_10.1.58
- https://tomcat.apache.org/security-9.html#Fixed_in_Apache_Tomcat_9.0.121
- https://tomcat.apache.org/security-10.html#Fixed_in_Apache_Tomcat_10.1.59