Stored cross-site scripting via polyglot photo upload
Published Aug 27, 2026 · Updated Aug 27, 2026
Stored cross-site scripting in Roskus Prospero Flow CRM before 5.16.0 allows remote authenticated users to execute JavaScript via a product photo. The photo rule checks magic bytes and blocks only listed PHP extensions, while ProductSaveController::save() preserves the client extension and copies the file into a public directory. A routine Seller role with create-product permission can upload an image-header HTML polyglot that the server returns as text/html in the application origin.
Summary
What happened
Stored cross-site scripting in Roskus Prospero Flow CRM before 5.16.0 allows remote authenticated users to execute JavaScript via a product photo. The photo rule checks magic bytes and blocks only listed PHP extensions, while ProductSaveController::save() preserves the client extension and copies the file into a public directory. A routine Seller role with create-product permission can upload an image-header HTML polyglot that the server returns as text/html in the application origin.
The record
- CVE
- CVE-2026-81931
- Published
- Aug 27, 2026
- Updated
- Aug 27, 2026
- Vendor
- Roskus
- Product
- Prospero Flow CRM
- Classifications
- CWE-434, T1059.007
- Attack vector
- network
- Privileges
- authenticated
Timeline
How it unfolded
- Aug 27, 2026CVE publishedPublication date reported by the CVE source.
- Aug 27, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=0 <5.16.0
What conditions does exploitation require?
What is affected?
Published CVSS scores
No CVSS assessment is available in this record.
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
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Technologies
Your stack
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Your stack
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