CVE-2026-59903CWE-524

CVE-2026-59903

Medium · published August 17, 2026

CVSS v3.1
6.5
EPSS
0%
Percentile
14.9
In the wild
Unconfirmed
What it is

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.

The record
Technical detail
CVSS v3.1
6.5 · MEDIUM
Vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:L/A:N
CVSS v4.0
Not supplied
EPSS
0.00246 · 14.9th percentile
Weakness
CWE-524 · Use of Cache Containing Sensitive Information
Published
2026-08-17T22:17Z
Affected products (2)
ProductVersionsFixed in
netty/netty< 4.1.1374.1.137
netty/netty≥ 4.2.0, < 4.2.174.2.17
References (5)
https://github.com/netty/netty/pull/17213 · [email protected]https://github.com/netty/netty/pull/17217 · [email protected]https://github.com/netty/netty/releases/tag/netty-4.1.137.Final · [email protected]https://github.com/netty/netty/releases/tag/netty-4.2.17.Final · [email protected]https://github.com/netty/netty/security/advisories/GHSA-8c42-7qj2-3j46 · [email protected]
EPSS history
Timeline
  • 17 AUG 17:56Z
    Netty: Cache Poisoning and Information Disclosure via CORS Vary Header Overwrite
    cvelistv5