CVE-2026-46685

Summary

RustFS is a distributed object storage system built in Rust. Prior to 1.0.0-beta.2, when RUSTFS_CORS_ALLOWED_ORIGINS is unset, the RustFS S3 listener's ConditionalCorsLayer reflects any request Origin value back as Access-Control-Allow-Origin and also sets Access-Control-Allow-Credentials: true and Access-Control-Allow-Headers: * on responses, including preflight responses and error responses. This creates a permissive cross-domain policy with untrusted origins. A browser visiting an attacker-controlled page can issue credentialed cross-origin requests to a reachable RustFS deployment and read the response when the victim browser has ambient credentials for the RustFS origin, such as saved HTTP Basic Auth credentials, reverse-proxy SSO cookies, or TLS client certificates. This vulnerability is fixed in 1.0.0-beta.2.

Affected Software

Weaknesses

• CWE-306: CWE-306: Missing Authentication for Critical Function
• CWE-346: CWE-346: Origin Validation Error
• CWE-942: CWE-942: Permissive Cross-domain Policy with Untrusted Domains

ADP Enrichment

CISA ADP Vulnrichment

• SSVC:
• Exploitation: poc
  • Automatable: no
  • Technical Impact: partial

Additional References

• https://github.com/rustfs/rustfs/security/advisories/GHSA-x5xv-223c-8vm7

References

• https://github.com/rustfs/rustfs/security/advisories/GHSA-x5xv-223c-8vm7

• ←Previous
• Next→