CVE-2026-22043

RustFS has IAM deny_only Short-Circuit that Allows Privilege Escalation via Service Account Minting

State: Published
Severity: 5.7 Medium
Published: Jan 8, 2026
Updated: Jan 8, 2026
Reserved: Jan 5, 2026

Description

RustFS is a distributed object storage system built in Rust. In versions 1.0.0-alpha.13 through 1.0.0-alpha.78, a flawed `deny_only` short-circuit in RustFS IAM allows a restricted service account or STS credential to self-issue an unrestricted service account, inheriting the parent’s full privileges. This enables privilege escalation and bypass of session/inline policy restrictions. Version 1.0.0-alpha.79 fixes the issue.

Scores

CVSS	Score	Vector	Source
4.0	5.7 Medium	CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N/E:P	GitHub_M

Weaknesses

CWE-269 Improper Privilege Management
CWE-284 Improper Access Control

Affected Products

Product	Versions
rustfsrustfs	>= 1.0.0-alpha.13, < 1.0.0-alpha.79Affected

References

https://github.com/rustfs/rustfs/security/advisories/GHSA-xgr5-qc6w-vcg9

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