CVE-2025-53506

Public on 2025-07-10
Modified on 2025-07-22
Description
Uncontrolled Resource Consumption vulnerability in Apache Tomcat if an HTTP/2 client did not acknowledge the initial settings frame that reduces the maximum permitted concurrent streams.

This issue affects Apache Tomcat: from 11.0.0-M1 through 11.0.8, from 10.1.0-M1 through 10.1.42, from 9.0.0.M1 through 9.0.106.

Users are recommended to upgrade to version 11.0.9, 10.1.43 or 9.0.107, which fix the issue.
Severity
Important severity
Important
See what this means
CVSS v3 Base Score
7.5
See breakdown

Affected Packages

Platform Package Release Date Advisory Status
Amazon Linux 2 - Tomcat9 Extra tomcat Pending Fix
Amazon Linux 2 - Core tomcat Not Affected
Amazon Linux 2023 tomcat10 Pending Fix
Amazon Linux 1 tomcat7 No Fix Planned
Amazon Linux 1 tomcat8 No Fix Planned
Amazon Linux 1 tomcat80 No Fix Planned
Amazon Linux 2023 tomcat9 Pending Fix

CVSS Scores

Score Type Score Vector
Amazon Linux CVSSv3 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
NVD CVSSv3 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H