Information Exposure Through Caching Affecting s3proxy package, versions <4.0.0-r2
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-CHAINGUARDLATEST-S3PROXY-18955914
- published19 Aug 2026
- disclosed17 Aug 2026
Introduced: 17 Aug 2026
NewCVE-2026-59903 (opens in a new tab)How to fix?
Upgrade Chainguard s3proxy to version 4.0.0-r2 or higher.
NVD Description
Note: Versions mentioned in the description apply only to the upstream s3proxy package and not the s3proxy package as distributed by Chainguard.
See How to fix? for Chainguard relevant fixed versions and status.
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.