Vulnerability · Published Mar 11, 2026 · Assigned by GitHub_M
CVE-2026-32101StudioCMS S3 Storage Manager Authorization Bypass via Missing `await` on Async Auth Check
High 7.6
In plain English
A high-severity incorrect authorization in s3-storage from @studiocms. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 12% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official description
StudioCMS is a server-side-rendered, Astro native, headless content management system. Prior to 0.3.1, the S3 storage manager's isAuthorized() function is declared async (returns Promise<boolean>) but is called without await in both the POST and PUT handlers. Since a Promise object is always truthy in JavaScript, !isAuthorized(type) always evaluates to false, completely bypassing the authorization check. Any authenticated user with the lowest visitor role can upload, delete, rename, and list all files in the S3 bucket. This vulnerability is fixed in 0.3.1.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| npm | @studiocms/s3-storage | 0.3.1 | GHSA-mm78-fgq8-6pgr |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| @studiocms | s3-storage | < 0.3.1 |
Weakness: CWE-863 · Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:H/A:L