CVE-2026-59903
Published:August 17, 2026
Updated:September 01, 2026
Netty is an asynchronous, event-driven network application framework. Prior to 4.1.137.Final and 4.2.17.Final, io.netty.handler.codec.http.cors.CorsHandler setVaryHeader replaces application Vary headers such as Authorization or Cookie with Origin, allowing a caching proxy or CDN to reuse authenticated responses across users and disclose sensitive information. This issue is fixed in versions 4.1.137.Final and 4.2.17.Final.
Affected Packages
https://github.com/netty/netty.git (GITHUB):
Affected version(s) >=netty-4.2.0.Final <netty-4.2.17.FinalFix Suggestion:
Update to version netty-4.2.17.Finalhttps://github.com/netty/netty.git (GITHUB):
Affected version(s) >=netty-4.0.0.Final <netty-4.1.137.FinalFix Suggestion:
Update to version netty-4.1.137.Finalio.netty:netty-codec-http (JAVA):
Affected version(s) >=4.2.0.Final <4.2.17.FinalFix Suggestion:
Update to version 4.2.17.Finalio.netty:netty-codec-http (JAVA):
Affected version(s) >=4.0.0.Alpha1 <4.1.137.FinalFix Suggestion:
Update to version 4.1.137.FinalRelated Resources (8)
Do you need more information?
Contact UsCVSS v4
Base Score:
8.3
Attack Vector
NETWORK
Attack Complexity
HIGH
Attack Requirements
NONE
Privileges Required
NONE
User Interaction
NONE
Vulnerable System Confidentiality
HIGH
Vulnerable System Integrity
LOW
Vulnerable System Availability
NONE
Subsequent System Confidentiality
NONE
Subsequent System Integrity
NONE
Subsequent System Availability
NONE
CVSS v3
Base Score:
6.5
Attack Vector
NETWORK
Attack Complexity
HIGH
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
HIGH
Integrity
LOW
Availability
NONE
Weakness Type (CWE)
Use of Cache Containing Sensitive Information
EPSS
Base Score:
0.24