Resource exhaustion in Apache Tomcat

CVE-2025-53506

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 th…

Vulnerability class: DoS (Denial of Service)

EPSS: 0.019 (77.1th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.

Affected products

Weakness classification (CWE)

Public proof-of-concept exploits

References

Frequently asked questions

What is CVE-2025-53506?
CVE-2025-53506 is a high-severity vulnerability in Apache Tomcat, classified under Uncontrolled Resource Consumption. CVSS score: 7.5/10. Published 2025-07-10.
How severe is CVE-2025-53506?
High severity. CVSS v3 base score is 7.5 out of 10.
Is CVE-2025-53506 known to be exploited?
3 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.