CVE-2026-30948
MEDIUM
GHSA-hcj7-6gxh-24ww
CVSS Vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N
Lifecycle Timeline
3Tags
Description
Parse Server is an open source backend that can be deployed to any infrastructure that can run Node.js. Prior to 9.5.2-alpha.4 and 8.6.17, a stored cross-site scripting (XSS) vulnerability allows any authenticated user to upload an SVG file containing JavaScript. The file is served inline with Content-Type: image/svg+xml and without protective headers, causing the browser to execute embedded scripts in the Parse Server origin. This can be exploited to steal session tokens from localStorage and achieve account takeover. The default fileExtensions option blocks HTML file extensions but does not block SVG, which is a well-known XSS vector. All Parse Server deployments where file upload is enabled for authenticated users (the default) are affected. This vulnerability is fixed in 9.5.2-alpha.4 and 8.6.17.
Analysis
Parse Server versions prior to 9.5.2-alpha.4 and 8.6.17 allow authenticated users to upload SVG files containing malicious JavaScript that executes in the server's origin context due to missing content security headers, enabling attackers to steal session tokens and compromise user accounts. All deployments with file upload enabled for authenticated users are vulnerable by default, as the file extension filter blocks HTML but not SVG files. …
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Remediation
Within 30 days: Identify affected systems and apply vendor patches as part of regular patch cycle. Verify Content-Security-Policy and output encoding.
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