# CVE-2026-59903: eap8-netty: Netty is an asynchronous, event-driven network application framework

CVE-2026-59903 is fixed in 5 products on 1 platform, first by RHSA-2026:92059, released August 17, 2026. It is not reported as exploited. Patch Radar priority: Routine.

- Web page: https://patchblox.com/security/cve/CVE-2026-59903
- Priority: Routine
- CVSS: 6.5 (moderate)
- EPSS: 0.0032
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Aug 17, 2026

## 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.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | eap8-netty RHEL 10 | 4.1.138-1.Final_redhat_00001.1.el10eap | [RHSA-2026:92059](https://patchblox.com/security/data/fix/linux/rhsa-2026-92059.md) | Aug 17, 2026 |
| Linux | eap8-netty-transport-native-epoll RHEL 10 | 4.1.138-1.Final_redhat_00001.1.el10eap | [RHSA-2026:92059](https://patchblox.com/security/data/fix/linux/rhsa-2026-92059.md) | Aug 17, 2026 |
| Linux | eap8-resteasy RHEL 10 | 6.2.19-1.Final_redhat_00002.1.el10eap | [RHSA-2026:92059](https://patchblox.com/security/data/fix/linux/rhsa-2026-92059.md) | Aug 17, 2026 |
| Linux | netty sles 15.7 | 4.1.138-150200.4.56.1 | [SUSE-SU-2026:4391-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-4391-1.md) | Sep 29, 2026 |
| Linux | netty-tcnative sles 15.6 | 2.0.84-150200.3.51.1 | [SUSE-SU-2026:4391-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-4391-1.md) | Sep 29, 2026 |
| Linux | netty-tcnative sles 15.7 | 2.0.84-150200.3.51.1 | [SUSE-SU-2026:4391-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-4391-1.md) | Sep 29, 2026 |

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Data as of 2026-11-09T01:18:40Z UTC. Source: Patchblox Patch Radar (https://patchblox.com/security/patch-radar). Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

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