Executive brief
RustFS, a distributed storage system, may inadvertently leak sensitive security credentials into its system logs when debug logging is enabled. These logs can contain full authentication tokens and secret access keys in plain text, which could allow anyone with access to the logs to impersonate users or gain unauthorized access to stored data. This issue affects versions prior to 1.0.0-beta.2.
Technical details
RustFS prior to version 1.0.0-beta.2 contains two distinct logging vulnerabilities that leak credentials when RUST_LOG=debug is set. First, the STS (Security Token Service) handler prints the Credentials struct using the Debug trait, which fails to mask the session_token (JWT). Second, the s3s dependency logs the full HTTP response body for STS API calls, which includes the SecretAccessKey and SessionToken in plaintext XML. An attacker with access to the server logs could use these leaked credentials to perform unauthorized actions. The fix involves implementing a Masked wrapper for sensitive fields in the Credentials struct and redacting the response body content in the s3s service.
Affected products
- rustfs RustFS < 1.0.0-beta.2
Timeline
- 2026-05-09: advisory: GitHub Security Advisory published
- 2026-05-28: disclosed: CVE published to NVD