CVE-2026-59903 PUBLISHED

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.

• https://github.com/netty/netty/security/advisories/GHSA-8c42-7qj2-3j46
• 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

• CWE-524: Use of Cache Containing Sensitive Information CWE