CVE-2026-81931: Unrestricted upload of file with dangerous type in Prospero Flow CRM product photo allows stored cross-site scripting
Unrestricted Upload of File with Dangerous Type in the product photo upload in Roskus Prospero Flow CRM before 5.16.0 allows an authenticated user holding the create product permission (routine Seller role) to execute arbitrary JavaScript in the application origin. The photo validation rule classifies the file only by its content (magic bytes) and rejects only a fixed list of PHP extensions, while ProductSaveController::save() names the stored file using the client-supplied extension and copies it into the public web root. A file that begins with an image header and carries an HTML extension passes validation, is stored under public/asset/upload/product/, and is served with a text/html content type, turning the upload into first-party stored script execution.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
Roskus Prospero Flow CRMto a version that resolves this vulnerability.Fixed in 5.16.0 - Remove
Remove
public/asset/upload/product/ (files with non-image extension)from your environment.Review and remove any existing files with a non-image extension under public/asset/upload/product/.
Event History
Frequently Asked Questions
Who can exploit this issue?
An authenticated user with permission to create products can exploit it. The affected permission is described as part of the routine Seller role.
Which deployments are affected?
Roskus Prospero Flow CRM versions before 5.16.0 are affected. The vulnerable upload path places product photos under the publicly served public/asset/upload/product/ directory.
What does an attacker need to upload?
The attacker needs a file that starts with an image header so it passes content-based validation, while using an HTML extension supplied by the client. The application preserves that extension and serves the resulting file as text/html, allowing JavaScript execution in the application origin.
How can administrators identify potentially malicious uploads?
Review files in public/asset/upload/product/ for HTML files or other unexpected client-supplied extensions, particularly files that contain an image header but include HTML or JavaScript content. Such files may have been accepted as product photos and publicly served as HTML.