CVE-2026-59903: Netty: Cache Poisoning and Information Disclosure via CORS Vary Header Overwrite
Medium · CVSS 6.5 (CVSS 3.1)EPSS 0.32%, 25th percentilePublished Updated Assigner: GitHub_M
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.
Vector CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:L/A:N · CWE-524
Tracked companies
Mapped from the CVE’s affected-product data, NVD CPE matches, vendor advisories or package feeds. A mapping means the vendor’s software is named, not that its hosted service was exposed.
Status incidents that name it
No tracked status incident names this CVE.
Affected vendors and products
netty: netty
References
- CVE record on cve.org (opens in new tab)
- NVD entry (opens in new tab)
- github.com/netty/netty/pull/17213 (opens in new tab)
- github.com/netty/netty/pull/17217 (opens in new tab)
- github.com/netty/netty/releases/tag/netty-4.1.137.Final (opens in new tab)
- github.com/netty/netty/releases/tag/netty-4.2.17.Final (opens in new tab)
- github.com/netty/netty/security/advisories/GHSA-8c42-7qj2-3j46 (opens in new tab)
- CVE records from the CVE Program (cve.org). CVE® is a registered trademark of The MITRE Corporation. (opens in new tab)
- This product uses data from the NVD API but is not endorsed or certified by the NVD. (opens in new tab)
- Known Exploited Vulnerabilities catalog from CISA. (opens in new tab)
- EPSS scores from FIRST (Exploit Prediction Scoring System). (opens in new tab)