CVE-2026-93491
Published:September 18, 2026
Updated:September 22, 2026
A flaw was found in Netty's HttpServerCodec. A remote, unauthenticated attacker can exploit this vulnerability by pipelining HTTP/1.1 requests on a single connection and withholding reads. This action causes the methodOverflowQueue to grow without limit, leading to unbounded heap memory consumption and a denial of service due to memory exhaustion.
Affected Packages
https://github.com/netty/netty.git (GITHUB):
Affected version(s) >=netty-4.1.7.Final <netty-4.1.138.FinalFix Suggestion:
Update to version netty-4.1.138.Finalhttps://github.com/netty/netty.git (GITHUB):
Affected version(s) >=netty-4.2.0.Alpha1 <netty-4.2.18.FinalFix Suggestion:
Update to version netty-4.2.18.Finalio.netty:netty-codec-http (JAVA):
Affected version(s) >=4.2.0.Alpha1 <4.2.18.FinalFix Suggestion:
Update to version 4.2.18.Finalio.netty:netty-codec-http (JAVA):
Affected version(s) >=4.1.7.Final <4.1.138.FinalFix Suggestion:
Update to version 4.1.138.Finalio.netty:netty-codec-http (JAVA):
Affected version(s) >=4.0.43.Final <Related Resources (6)
Do you need more information?
Contact UsCVSS v4
Base Score:
8.7
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
HIGH
Subsequent System Confidentiality
NONE
Subsequent System Integrity
NONE
Subsequent System Availability
NONE
CVSS v3
Base Score:
7.5
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
NONE
Availability
HIGH
Weakness Type (CWE)
Allocation of Resources Without Limits or Throttling
EPSS
Base Score:
0.44