CVE-2026-32101
📋 TL;DR
This vulnerability allows any authenticated user, even with the lowest 'visitor' role, to bypass authorization checks and perform unauthorized file operations on S3 storage. Affected systems are StudioCMS installations prior to version 0.3.1 that use S3 storage functionality.
💻 Affected Systems
- StudioCMS
⚠️ Manual Verification Required
This CVE does not have specific version information in our database, so automatic vulnerability detection cannot determine if your system is affected.
Why? The CVE database entry doesn't specify which versions are vulnerable (no version ranges provided by the vendor/NVD).
🔒 Custom verification scripts are available for registered users. Sign up free to download automated test scripts.
- Review the CVE details at NVD
- Check vendor security advisories for your specific version
- Test if the vulnerability is exploitable in your environment
- Consider updating to the latest version as a precaution
⚠️ Risk & Real-World Impact
Worst Case
Complete compromise of S3 bucket contents - attackers can upload malicious files, delete critical data, rename files to disrupt operations, and enumerate all stored files.
Likely Case
Unauthorized users accessing, modifying, or deleting sensitive files stored in S3 buckets, potentially leading to data loss, data corruption, or unauthorized data exposure.
If Mitigated
Limited impact if S3 bucket permissions are properly configured at the AWS level or if file operations are monitored and restricted through additional controls.
🎯 Exploit Status
Exploitation requires authenticated access but is trivial once authenticated due to the simple authorization bypass logic.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 0.3.1
Vendor Advisory: https://github.com/withstudiocms/studiocms/security/advisories/GHSA-mm78-fgq8-6pgr
Restart Required: Yes
Instructions:
1. Update StudioCMS to version 0.3.1 or later. 2. Restart the StudioCMS application. 3. Verify the fix by testing authorization checks for S3 operations.
🔧 Temporary Workarounds
Disable S3 Storage
allTemporarily disable S3 storage functionality until patching is possible.
Modify StudioCMS configuration to use local storage instead of S3
Restrict S3 Bucket Permissions
allConfigure AWS S3 bucket policies to restrict access only to necessary operations from the StudioCMS application.
aws s3api put-bucket-policy --bucket BUCKET_NAME --policy file://restrictive-policy.json
🧯 If You Can't Patch
- Implement strict AWS S3 bucket policies with least privilege access
- Monitor and alert on all S3 file operations from StudioCMS users
🔍 How to Verify
Check if Vulnerable:
Check StudioCMS version - if below 0.3.1 and using S3 storage, the system is vulnerable. Test by attempting S3 file operations with a low-privilege user account.Check Version:
Check package.json or StudioCMS admin interface for version numberVerify Fix Applied:
After updating to 0.3.1+, verify that low-privilege users cannot perform unauthorized S3 file operations. Check that authorization checks are properly enforced.📡 Detection & Monitoring
Log Indicators:
- Unauthorized S3 file operations in application logs
- Failed authorization attempts that should have succeeded
- S3 API calls from low-privilege user accounts
Network Indicators:
- Unexpected S3 API traffic from StudioCMS instances
- File uploads/deletions from unauthorized users
SIEM Query:
source="studiocms" AND (event="file_upload" OR event="file_delete") AND user_role="visitor"