CVE-2026-59903mediumCWE-524

CVE-2026-59903: medium-severity vulnerability in netty

Netty: Cache Poisoning and Information Disclosure via CORS Vary Header Overwrite

Published

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33Vexday Risk Score

No sign of exploitation. It has a public proof of concept.

ssvc Attendcvss 6.5epss 0.3%
from disclosure to weapon22 days
Published on NVDAug 17
1st PoC+22d
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/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:L/A:N
Affected products
netty · netty
⚠ Public resources, to assess the exposure of systems you control or are authorized to test. Test only with authorization.
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