Vulnerability Details CVE-2026-59903
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.
Exploit prediction scoring system (EPSS) score
EPSS Score 0.002
EPSS Ranking 16.0%
CVSS Severity
CVSS v3 Score 6.5