Open-Source Security Intelligence

Know every vulnerability
before it knows you.

DevGuard continuously monitors your dependencies and alerts you when CVEs like this one affect your stack — with real-time threat intelligence built for developers.

Search

CVE-2026-59903

MediumCVSS 6.5 / 10
Published Aug 17, 2026·Last modified Aug 18, 2026
Affected Components(204)
netty/netty
netty-4.1.7.Final
netty/netty
netty-4.0.0.CR2
netty/netty
netty-4.1.58.Final
1 / 68
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.

Upload your SBOM

Upload your own SBOM in CycloneDX 1.6 or higher (JSON) directly here to check your vulnerabilities.

Risk Scores
Base Score
6.5

The vulnerability can be exploited over the network without needing physical access. It is difficult for an attacker to exploit this vulnerability and may require special conditions. An attacker does not need any special privileges or access rights. No user interaction is needed for the attacker to exploit this vulnerability. The impact is confined to the system where the vulnerability exists. There is a high impact on the confidentiality of the information. There is a low impact on the integrity of the data.

Threat Intelligence
6.2

Exploitation attempts have been detected. Elevated vigilance and prompt remediation are advised.

EPSS
0.25%

The exploit probability is very low. The vulnerability is unlikely to be exploited in the next 30 days.

Exploit
Proof of Concept

A proof of concept is available for this vulnerability (1 exploit found).

Scan your project

Continuously monitor your dependencies and get alerted when vulnerabilities like this one affect your stack.

Checkout DevGuard