Vulnerability Description
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.
CVSS Score
MEDIUM
Related Weaknesses (CWE)
References
- https://github.com/netty/netty/pull/17213
- https://github.com/netty/netty/pull/17217
- https://github.com/netty/netty/releases/tag/netty-4.1.137.Final
- https://github.com/netty/netty/releases/tag/netty-4.2.17.Final
- https://github.com/netty/netty/security/advisories/GHSA-8c42-7qj2-3j46
FAQ
What is CVE-2026-59903?
CVE-2026-59903 is a vulnerability with a CVSS score of 6.5 (MEDIUM). 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 head...
How severe is CVE-2026-59903?
CVE-2026-59903 has been rated MEDIUM with a CVSS base score of 6.5/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2026-59903?
Check the references section above for vendor advisories and patch information. Review vendor security bulletins for remediation guidance.