Vulnerability Description
RustFS is a distributed object storage system built in Rust. Prior to 1.0.0-alpha.94, all four notification target admin API endpoints in `rustfs/src/admin/handlers/event.rs` use a `check_permissions` helper that validates authentication only (access key + session token), without performing any admin-action authorization via `validate_admin_request`. Every other admin handler in the codebase correctly calls `validate_admin_request` with a specific `AdminAction`. This is the only admin handler file that skips authorization. A non-admin user can overwrite a shared admin-defined notification target by name, causing subsequent bucket events to be delivered to an attacker-controlled endpoint. This enables cross-user event interception and audit evasion. 1.0.0-alpha.94 contains a patch.
CVSS Score
HIGH
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Rustfs | Rustfs | 1.0.0 |
Related Weaknesses (CWE)
References
- https://github.com/rustfs/rustfs/releases/tag/1.0.0-alpha.94ProductRelease Notes
- https://github.com/rustfs/rustfs/security/advisories/GHSA-pfcq-4gjr-6gjmMitigationVendor Advisory
FAQ
What is CVE-2026-40937?
CVE-2026-40937 is a vulnerability with a CVSS score of 8.3 (HIGH). RustFS is a distributed object storage system built in Rust. Prior to 1.0.0-alpha.94, all four notification target admin API endpoints in `rustfs/src/admin/handlers/event.rs` use a `check_permissions`...
How severe is CVE-2026-40937?
CVE-2026-40937 has been rated HIGH with a CVSS base score of 8.3/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2026-40937?
Check the references section above for vendor advisories and patch information. Affected products include: Rustfs Rustfs.