---
id: CVE-2026-61448
title: >-
  Parse Server is affected by a stored cross-site scripting (XSS) vulnerability
  in versions >= 9.0.0, < 9.10.0-alpha.2 and <= 8.6.83
summary: >-
  Parse Server is affected by a stored cross-site scripting (XSS) vulnerability
  in versions >= 9.0.0, < 9.10.0-alpha.2 and <= 8.6.83. When an uploaded file's
  extension is not recognized by the mime package, Parse Server preserves the
  clien…
severity: none
cwe:
  - CWE-434
published: '2026-07-11'
updated: '2026-07-11'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-61448'
references:
  - url: >-
      https://github.com/parse-community/parse-server/security/advisories/GHSA-r899-h629-j84r
    label: disclosure@vulncheck.com
  - url: >-
      https://www.vulncheck.com/advisories/parse-server-stored-xss-via-malformed-content-type
    label: disclosure@vulncheck.com
tags:
  - nvd
ingestedAt: '2026-07-11T23:16:21.413Z'
epss: 0.00415
epssPercentile: 0.3299
---

## Overview

Parse Server is affected by a stored cross-site scripting (XSS) vulnerability in versions >= 9.0.0, < 9.10.0-alpha.2 and <= 8.6.83. When an uploaded file's extension is not recognized by the mime package, Parse Server preserves the client-supplied Content-Type. A malformed Content-Type that is not a valid type/subtype media type (e.g., 'image', 'image/', or 'image//svg+xml') bypasses the fileUpload.fileExtensions blocklist and is stored unchanged. On storage adapters that persist and serve the uploaded Content-Type (such as Amazon S3, Google Cloud Storage, or Azure Blob Storage), a browser cannot parse the malformed value and falls back to MIME-sniffing; a file whose body begins with HTML is rendered as HTML, executing embedded script in the application's origin against other users who open the file URL. The default GridFS storage adapter is not affected. Fixed in 9.10.0-alpha.2 and 8.6.84.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.