StudioCMS S3 Storage Manager Authorization Bypass via Missing `await` on Async Auth Check
Published Mar 11, 2026
7.6
HIGHCVSS 3.1
EPSS 0.28%
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 products
- Vendor n/a Product S3-Storage Defaultn/a
- Version < 0.3.1StatusaffectedConstraints-
- Version
Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).
| Vendor | Product | Default status | Versions | ||||||
|---|---|---|---|---|---|---|---|---|---|
| n/a | S3-Storage | n/a |
|
No data.
No Red Hat product state for this CVE.
@studiocms/s3-storage
npm
Introduced 0 Fixed 0.3.1
| Ecosystem | Package | Introduced | Fixed |
|---|---|---|---|
| npm | @studiocms/s3-storage | 0 | 0.3.1 |
Remediation
No remediation recorded yet.
Metrics
No CVSS v4.0 score for this CVE.
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L
1 other source (GHSA) ▾
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:H/A:L
No CVSS v3.0 score for this CVE.
No CVSS v2.0 score for this CVE.
This CVE is not in the KEV list.
CISA SSVC (Vulnrichment)
Stakeholder-Specific Vulnerability Categorization from CISA ADP.
Exploitation
PoCAutomatable
NoTechnical Impact
PartialDecision
n/aAssessed Mar 12, 2026 · SSVC 2.0.3
Estimated probability of exploitation in the wild in the next 30 days (FIRST EPSS). As of Oct 1, 2026.
Score over time
Mar–Oct 2026- EPSS v4
- EPSS v5
Percentile over time
- EPSS v4
- EPSS v5
Table of values (3 key points)
Flat stretches are collapsed; showing up to 120 newest points.
| Date | Score | Percentile | Model |
|---|---|---|---|
| Oct 1, 2026 | 0.28% (0.00278) | 18.33th | v5 (v2026.06.15) |
| Jun 15, 2026 | 0.18% (0.00183) | 8.04th | v5 (v2026.06.15) |
| Mar 12, 2026 | 0.03% (0.00034) | 9.58th | v4 (v2025.03.14) |
References (3)
- https://github.com/advisories/GHSA-mm78-fgq8-6pgr Advisory
- https://github.com/withstudiocms/studiocms/security/advisories/GHSA-mm78-fgq8-6pgr x_refsource_CONFIRMExploitVendor Advisory
- https://nvd.nist.gov/vuln/detail/CVE-2026-32101
| Link | Providers | Tags |
|---|---|---|
| https://github.com/advisories/GHSA-mm78-fgq8-6pgr | Advisory | |
| https://github.com/withstudiocms/studiocms/security/advisories/GHSA-mm78-fgq8-6pgr | x_refsource_CONFIRMExploitVendor Advisory | |
| https://nvd.nist.gov/vuln/detail/CVE-2026-32101 |
Change history (0)
No recorded changes yet.