Vulnerability · Published Jan 8, 2026 · Assigned by GitHub_M

CVE-2026-22043RustFS has IAM deny_only Short-Circuit that Allows Privilege Escalation via Service Account Minting

Medium 5.7

In plain English

A medium-severity privilege mismanagement in rustfs from rustfs. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 36% of all known vulnerabilities).

Severity (CVSS 4.0)5.7Medium

Exploit odds (30 days)0.4%top 63.5% of all CVEs

Exploited in the wildNo reportsCISA SSVC: poc

Attack toolingNoneno public tooling known

Official 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.

Affected products (as reported)

Vendor	Product	Versions
rustfs	rustfs	>= 1.0.0-alpha.13, < 1.0.0-alpha.79

Weakness: CWE-269, CWE-284 · Vector: 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

References

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