VulnerabilityUndergoing Analysis

CVE-2026-59903

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…

MEDIUM 6.5EPSS 0.24%

Does this matter?

Lower severity and a low EPSS score (0.24%). Track it; it rarely justifies an emergency change on its own.

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.

CVSS 3.1: 6.5 MEDIUMCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:L/A:N
EPSS: 0.24% probability · 16th percentile
CISA KEV: Not listed
Weakness: CWE-524
Source: security-advisories@github.com

References

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.