XSS in Parse-Community Parse-Server
CVE-2026-30948
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.
Vulnerability class: XSS (Cross-Site Scripting)
EPSS: 0.002 (12.2th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 5.4 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N.
Affected products
- Parse-community Parse-server — versions >= 9.0.0 < 9.5.2-alpha.4, < 8.6.17
- Parseplatform Parse-server — versions 9.5.2
Weakness classification (CWE)
References
- security-advisories@github.com (x_refsource_CONFIRM, Patch, Mitigation, Vendor Advisory)
- security-advisories@github.com (Product, x_refsource_MISC, Release Notes)
- security-advisories@github.com (Product, x_refsource_MISC, Release Notes)
Frequently asked questions
- What is CVE-2026-30948?
- CVE-2026-30948 is a medium-severity vulnerability in Parse-Community Parse-Server, classified under Cross-site Scripting. CVSS score: 5.4/10. Published 2026-03-10.
- How severe is CVE-2026-30948?
- Medium severity. CVSS v3 base score is 5.4 out of 10.