Use of Cache Containing Sensitive Information Affecting io.netty:netty-codec-http package, versions [,4.1.137.Final)[4.2.0.Final,4.2.17.Final)
Threat Intelligence
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
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Test your applications- Snyk IDSNYK-JAVA-IONETTY-18956131
- published19 Aug 2026
- disclosed17 Aug 2026
- creditvioletagg
Introduced: 17 Aug 2026
NewCVE-2026-59903 (opens in a new tab)How to fix?
Upgrade io.netty:netty-codec-http to version 4.1.137.Final, 4.2.17.Final or higher.
Overview
io.netty:netty-codec-http is a network application framework for rapid development of maintainable high performance protocol servers & clients.
Affected versions of this package are vulnerable to Use of Cache Containing Sensitive Information due to the setVaryHeader method in codec-http/src/main/java/io/netty/handler/codec/http/cors/CorsHandler.java. An attacker can retrieve another user’s cached sensitive response by sending a cross-origin request that causes CorsHandler to overwrite an application’s existing Vary header, such as Vary: Authorization or Vary: Cookie, with Vary: Origin. Because shared caches and CDNs key the response on the reduced Vary set, user-specific responses can be cached and served to unauthorized clients. This can expose authenticated content or other sensitive data to other application users.