Resource exhaustion in Netty

CVE-2025-55163

Netty is an asynchronous, event-driven network application framework. Prior to versions 4.1.124.Final and 4.2.4.Final, Netty is vulnerable to MadeYouReset DDoS. This is a logical vulnerability in the HTTP/2 protocol, that uses malformed HTTP/2 control frames in order to break the max concurrent streams limit - which results in resource exhaustion and distributed denial of service. This issue has been patched in versions 4.1.124.Final and 4.2.4.Final.

Published · last modified .

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.

EPSS exploit prediction

EPSS: 0.011 (64.3th percentile), scored .

Low probability of exploitation in the next 30 days, but still tracked. 64th percentile — 64.3% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2025-55163: held from 0.010 to 0.011.

EPSS over last 30 days · oldest: 0.010 · newest: 0.011 · change: +0.001

Affected products

  • Netty — versions < 4.1.124.Final, < 4.2.4.Final

Weakness classification (CWE)

Public proof-of-concept exploits

References

Frequently asked questions

What is CVE-2025-55163?
CVE-2025-55163 is a high-severity vulnerability in Netty, classified under Allocation of Resources Without Limits or Throttling. CVSS score: 7.5/10. Published 2025-08-13.
How severe is CVE-2025-55163?
High severity. CVSS v3 base score is 7.5 out of 10.
Is CVE-2025-55163 known to be exploited?
4 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.