Quick answers
- Is CVE-2026-46685 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-46685 being exploited in the wild.
- How severe is CVE-2026-46685?
- Informational severity, with a CVSS score of 6, published 28 May 2026.
- Which products and versions are affected?
- RustFS RustFS < 1.0.0-beta.2.
- Is there a fix for CVE-2026-46685?
- A patch was published on 2026-05-28: Fixed in version 1.0.0-beta.2 Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
- How is CVE-2026-46685 attacked?
- It is attacked over the network, in a hosted service.
- Am I affected by CVE-2026-46685?
- Check whether anything you run is named in the advisory. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.
Technical details
A permissive Cross-Origin Resource Sharing (CORS) policy exists in the RustFS S3 listener's ConditionalCorsLayer. When the RUSTFS_CORS_ALLOWED_ORIGINS environment variable is unset, the application reflects any 'Origin' header from a request back into the 'Access-Control-Allow-Origin' response header. It simultaneously sets 'Access-Control-Allow-Credentials' to true. This combination allows an attacker-controlled website to perform credentialed requests (using cookies, Basic Auth, or TLS certificates) via a victim's browser and read the resulting responses. The vulnerability is rooted in rustfs/src/server/layer.rs and is fixed in version 1.0.0-beta.2 by changing the default behavior to emit no CORS headers when unconfigured.
Affected products
- RustFS RustFS < 1.0.0-beta.2
Timeline
- 2026-05-25: advisory: GitHub Security Advisory published
- 2026-05-28: disclosed: CVE published to NVD
- 2026-05-28: patched: Fixed in version 1.0.0-beta.2