CVE-2026-45039

RustFS: Internode RPC HMAC secret falls back to public default credential, enabling peer impersonation

State: Published
Severity: 9.8 Critical
Published: May 28, 2026
Updated: May 30, 2026
Reserved: May 8, 2026

Description

RustFS is a distributed object storage system built in Rust. Prior to 1.0.0-beta.2, the internode RPC layer authenticates every request with an HMAC-SHA256 signature using a shared secret. The function that produces this secret, get_shared_secret() in crates/ecstore/src/rpc/http_auth.rs, falls back to the public, source-tree-embedded DEFAULT_SECRET_KEY = "rustfsadmin" when neither the RUSTFS_RPC_SECRET environment variable nor the global S3 secret key has been configured. This vulnerability is fixed in 1.0.0-beta.2.

Scores

CVSS	Score	Vector	Source
3.1	9.8 Critical	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H	GitHub_M

Weaknesses

CWE-798 Use of Hard-coded Credentials
CWE-1392 Use of Default Credentials

Affected Products

Product	Versions
rustfsrustfs	< 1.0.0-beta.2Affected

References

https://github.com/rustfs/rustfs/security/advisories/GHSA-r5qv-rc46-hv8q

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