by Kastro
Paper/Archive/CVE-2026-22043

CVE-2026-22043

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

EPSS 0.4%public exploitCVSS 9.8
critical.is priorityof 100
47
CVSS 9.8 (NVD)9.8 / 10 × 3029.4Not in CISA KEV+300.0EPSS percentile 36.3.363 × 207.3Exploit: SSVC poc+1010.0SSVC exploitation: poc+100.0
Description · from the CVE record

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.

Affected

ProductAffectedFixed inSource
rustfs>= 1.0.0-alpha.13, < 1.0.0-alpha.79–CNA

Scores by source

NVD9.8CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
GitHub_M (CNA)5.7CVSS: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
CISA ADPSSVCExploitation: poc · Automatable: no · Technical impact: partial

References

exploitgithub.com/rustfs/rustfs/security/advisories/GHSA-xgr5-qc6w-vcg9