CVE-2025-53506

10.07.2025, 20:15

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.
The following versions were EOL at the time the CVE was created but are
known to be affected: 8.5.0 through 8.5.100.

Users are recommended to upgrade to version 11.0.9, 10.1.43 or 9.0.107, which fix the issue.

Provider	Type	Base Score	Atk. Vector	Atk. Complexity	Priv. Required	Vector
NIST	NIST	7.5 HIGH	NETWORK	LOW	NONE	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
apache	CNA	---				---
CISA-ADP	ADP	7.5 HIGH	NETWORK	LOW	NONE	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Base Score

CVSS 3.x

EPSS Score

Percentile: 37%

Vendor	Product	Version
apache	tomcat	9.0.0 ≤ 𝑥 ≤ 9.0.106
apache	tomcat	10.1.0 ≤ 𝑥 ≤ 10.1.42
apache	tomcat	11.0.0 ≤ 𝑥 ≤ 11.0.8

𝑥

= Vulnerable software versions

Common Weakness Enumeration

CWE-400 - Uncontrolled Resource Consumption
The software does not properly control the allocation and maintenance of a limited resource, thereby enabling an actor to influence the amount of resources consumed, eventually leading to the exhaustion of available resources.

Vulnerability Media Exposure

References

https://lists.apache.org/thread/p09775q0rd185m6zz98krg0fp45j8kr0