CVE-2026-93492
Published:September 18, 2026
Updated:October 09, 2026
A flaw was found in Netty's HTTP/2 HpackEncoder. A remote attacker can exploit this by sending HTTP/2 SETTINGS frames with a very large MAX_HEADER_TABLE_SIZE. This causes the HpackEncoder to store an excessive number of unique headers, leading to increased CPU usage and memory consumption, ultimately resulting in a Denial of Service (DoS).
Affected Packages
https://github.com/netty/netty.git (GITHUB):
Affected version(s) >=netty-4.2.0.Final <netty-4.2.18.FinalFix Suggestion:
Update to version netty-4.2.18.Finalhttps://github.com/netty/netty.git (GITHUB):
Affected version(s) >=netty-4.1.0.Beta4 <netty-4.1.138.FinalFix Suggestion:
Update to version netty-4.1.138.Finalio.netty:netty-codec-http2 (JAVA):
Affected version(s) >=4.1.0.Beta4 <4.1.138.FinalFix Suggestion:
Update to version 4.1.138.Finalio.netty:netty-codec-http2 (JAVA):
Affected version(s) >=4.2.0.Final <4.2.18.FinalFix Suggestion:
Update to version 4.2.18.Finalio.netty:netty-all (JAVA):
Affected version(s) >=4.1.0.Beta5 <4.1.138.FinalFix Suggestion:
Update to version 4.1.138.FinalRelated Resources (5)
Do you need more information?
Contact UsCVSS v4
Base Score:
6.9
Attack Vector
NETWORK
Attack Complexity
LOW
Attack Requirements
NONE
Privileges Required
NONE
User Interaction
NONE
Vulnerable System Confidentiality
NONE
Vulnerable System Integrity
NONE
Vulnerable System Availability
LOW
Subsequent System Confidentiality
NONE
Subsequent System Integrity
NONE
Subsequent System Availability
NONE
CVSS v3
Base Score:
5.3
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
NONE
Availability
LOW
EPSS
Base Score:
0.37