CVE-2026-32101 StudioCMS S3 Storage Manager Authorization Bypass via Missing `await` on Async Auth Check
Low-privilege users can bypass authorization checks to upload, delete, and list all files in the S3 bucket due to a missing await keyword.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-32101?
CVE-2026-32101 is a high-severity missing authorization vulnerability in @studiocms s3-storage, published on 11 Mar 2026. Any signed-in user can exploit it over the network, with no action from the victim.
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.
Weakness: CWE-863
Which versions are affected by CVE-2026-32101?
2 open source packages ship an affected version, including @studiocms/s3-storage. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
@studiocms/s3-storage npm | All versions | 0.3.1 |
@studiocms/s3-storage npm | All versions | 0.3.1 |
Products include Studiocms Studiocms.
How do I fix CVE-2026-32101?
Upgrade @studiocms/s3-storage to 0.3.1 or later.
Upgrade, and check permissions on every request on the server, not only in the interface. More about Missing authorization.
Is CVE-2026-32101 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-32101 exists.
Other vulnerabilities in @studiocms s3-storage
- CVE-2026-30944 StudioCMS Affected by Privilege Escalation via Insecure API Token Generation
- CVE-2026-30945 StudioCMS: IDOR — Arbitrary API Token Revocation Leading to Denial of Service
- CVE-2026-32103 StudioCMS: IDOR — Admin-to-Owner Account Takeover via Password Reset Link Generation
- CVE-2026-24134 StudioCMS has an Authorization Bypass Through User-Controlled Key
- CVE-2026-32104 StudioCMS: IDOR in User Notification Preferences Allows Any Authenticated User to Modify Any User's Settings
Sources
Also known as GHSA-mm78-fgq8-6pgr.