CVE-2026-22042

Description

### Summary The `ImportIam` admin API validates permissions using **`ExportIAMAction`** instead of **`ImportIAMAction`**, allowing a principal with *export-only* IAM permissions to perform *import* operations. Since importing IAM data performs privileged **write** actions (creating/updating users, groups, policies, and service accounts), this can lead to **unauthorized IAM modification and privilege escalation**. --- ### Details In `ImportIam`, the authorization check is implemented as follows: ```rust validate_admin_request( &req.headers, &cred, owner, false, vec![Action::AdminAction(AdminAction::ExportIAMAction)], ).await?; ``` However, this code resides in the **Import IAM** operation (`struct ImportIam {}`), which performs **state-changing IAM writes**. The expected behavior is to validate against **`AdminAction::ImportIAMAction`** (or an equivalent import-specific admin action), not `ExportIAMAction`. --- ### PoC **Prerequisites** 1. A RustFS deployment with IAM enabled. 2. An IAM user or role that has **Export IAM** permission but **does not** have Import IAM or full admin permissions. 3. Access credentials for that user. **Steps** 1. Create or obtain an IAM principal with permission equivalent to: ``` AdminAction::ExportIAMAction ``` and without Import IAM privileges. 2. Prepare a valid IAM import ZIP archive containing, for example: * A new policy granting administrative permissions * A user or service account bound to that policy 3. Send a request to the Import IAM endpoint (the same endpoint handled by `ImportIam::call`), authenticating with the export-only credentials. 4. Observe that: * The request passes authorization. * IAM entities from the archive are created or modified successfully. **Expected Result** * The request should be rejected with an authorization error (e.g., AccessDenied). **Actual Result** * The request succeeds, and IAM state is modified.

How to fix CVE-2026-22042

To remediate CVE-2026-22042, upgrade the affected package to a fixed version below.

• —upgrade to 1.0.0-alpha.79 or later

Is CVE-2026-22042 being exploited?

Low — EPSS is 0.0%, meaning exploitation activity has not been observed at scale.