CVE-2026-46685RustFS: Reflective CORS with credentials on S3 listener; unauthenticated license metadata endpoint on console

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.

CVSS

6.0 MEDIUM (v4.0, CNA)CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:H/VI:L/VA:N/SC:N/SI:N/SA:N

Weakness (CWE)

CWE-306, CWE-346, CWE-942

Known exploited

Not in CISA's KEV catalog

EPSS (exploitation in the next 30 days)

Not loaded for this CVE

Assigned by

GitHub_M

NVD analysis

Deferred

Record last updated

May 28, 2026

First seen by InfoSec Signals

Oct 9, 2026

The CVE record on cve.org · NVD's entry

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