High severity · published Aug 13, 2025
CVE-2025-55163
Netty is an asynchronous, event-driven network application framework
7.5
CVSS
1.1%
EPSS
No
On KEV
Description
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.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
None
Integrity
None
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)1.1% · higher than 66% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
NE
Netty · Netty
before 4.1.124; 4.2.0 before 4.2.4 · source: NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2025-55163
CVE.org
https://www.cve.org/CVERecord?id=CVE-2025-55163
Exploit
https://github.com/netty/netty/security/advisories/GHSA-prj3-ccx8-p6x4
www.openwall.com
http://www.openwall.com/lists/oss-security/2025/08/16/1
www.kb.cert.org
https://www.kb.cert.org/vuls/id/767506
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