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CVE PROGRAM SOURCE RECORD2.1 Low

CVE-2026-55778

Parse Server: Stored XSS via non-standard file extension bypassing file upload extension blocklist

Description

Parse Server is an open source backend that can be deployed to any infrastructure that can run Node.js. Prior to 9.9.1-alpha.11 and 8.6.81, the default fileUpload.fileExtensions blocklist could be bypassed by uploading a file with a non-standard or compound extension and dangerous content type, allowing storage adapters such as S3 and GCS to serve attacker-supplied active content and enable stored cross-site scripting. This issue is fixed in versions 9.9.1-alpha.11 and 8.6.81.

Affected products

Version statuses are supplied by the assigning organization. Consult the original record for detailed ranges and platform conditions.

parse-community parse-server

  • >= 9.0.0-alpha.1, < 9.9.1-alpha.11affected
  • < 8.6.81affected

References