in ResponsibleDisclosure, Cybersecurity, CVE, MITRE, OffensiveSecurity
CVE-2025-57520 – Stored XSS in Decap CMS (<= 3.8.3)
This vulnerability has been assigned CVE-2025-57520 by MITRE.
Vulnerability Summary
- Vulnerability Type: Stored Cross-Site Scripting (XSS)
- Affected Versions: Decap CMS <= 3.8.3
- Affected Component: Admin Panel → Content Preview Renderer (title, tags, description, body)
- Impact: Session hijacking, credential theft, arbitrary JavaScript execution in privileged user context
- Discoverer: Onurcan Genç – Independent Security Researcher
Scenario Flow
- Contributor (low privilege) injects a malicious payload into a blog entry.
- Editor/Admin (high privilege) later opens the entry in the preview panel.
- The payload executes in the privileged user’s browser context.
The vulnerability was verified under both contributor and editor roles. The most severe impact is observed when an admin user views the malicious entry in preview mode, leading to stored XSS execution in the privileged context.