CVE-2026-30948
Stored XSS in Parse Server SVG Upload Enables Account Takeover
Publication date: 2026-03-10
Last updated on: 2026-03-11
Assigner: GitHub, Inc.
Description
Description
CVSS Scores
EPSS Scores
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Meta Information
Affected Vendors & Products
| Vendor | Product | Version / Range |
|---|---|---|
| parseplatform | parse-server | 9.5.2 |
| parseplatform | parse-server | 9.5.2 |
| parseplatform | parse-server | 9.5.2 |
| parseplatform | parse-server | From 9.0.0 (inc) to 9.5.2 (exc) |
| parseplatform | parse-server | to 8.6.17 (exc) |
Helpful Resources
Exploitability
| CWE ID | Description |
|---|---|
| CWE-79 | The product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users. |
Attack-Flow Graph
AI Powered Q&A
Can you explain this vulnerability to me?
This vulnerability is a stored cross-site scripting (XSS) issue in Parse Server versions prior to 9.5.2-alpha.4 and 8.6.17. It allows any authenticated user to upload an SVG file that contains embedded JavaScript. Because the server serves the SVG file inline with the Content-Type set to image/svg+xml and without protective headers, the browser executes the embedded scripts within the context of the Parse Server origin.
The default configuration blocks HTML file extensions but does not block SVG files, which are a known vector for XSS attacks. This means that attackers can exploit this to run malicious scripts in other users' browsers.
How can this vulnerability impact me? :
The vulnerability can be exploited to steal session tokens stored in localStorage, which can lead to account takeover. This means an attacker could impersonate other users by hijacking their sessions.
Since the malicious script runs in the context of the Parse Server origin, it can perform actions on behalf of the victim user, potentially leading to unauthorized access to sensitive data or functionality.
How does this vulnerability affect compliance with common standards and regulations (like GDPR, HIPAA)?:
I don't know
How can this vulnerability be detected on my network or system? Can you suggest some commands?
I don't know
What immediate steps should I take to mitigate this vulnerability?
To mitigate this vulnerability, upgrade your Parse Server deployment to version 9.5.2-alpha.4 or later, or 8.6.17 or later, where the issue is fixed.
Additionally, consider disabling or restricting file uploads for authenticated users if not necessary, or implement additional filtering to block SVG file uploads, as SVG files are a known XSS vector.