Vulnerability Description
Parse Server is an open source backend that can be deployed to any infrastructure that can run Node.js. Prior to versions 8.6.79 and 9.9.1-alpha.4, the default file upload extension blocklist can be bypassed by appending a trailing dot to a filename whose extension would otherwise be blocked (e.g. poc.svg.). The trailing dot causes the extension parser to extract an empty string, which short-circuits the blocklist check, and the attacker-controlled Content-Type is forwarded to the storage adapter unchanged. Storage adapters that persist and serve the provided Content-Type (such as S3 or GCS) then serve the file with an active type such as image/svg+xml, enabling stored XSS when a victim opens the file URL. The default GridFS adapter is not affected because it sets X-Content-Type-Options: nosniff on responses. This issue has been patched in versions 8.6.79 and 9.9.1-alpha.4.
Related Weaknesses (CWE)
References
- https://github.com/parse-community/parse-server/pull/10489
- https://github.com/parse-community/parse-server/pull/10490
- https://github.com/parse-community/parse-server/security/advisories/GHSA-7wqv-xj
FAQ
What is CVE-2026-53724?
CVE-2026-53724 is a documented vulnerability. Parse Server is an open source backend that can be deployed to any infrastructure that can run Node.js. Prior to versions 8.6.79 and 9.9.1-alpha.4, the default file upload extension blocklist can be b...
How severe is CVE-2026-53724?
CVSS scoring is not yet available for CVE-2026-53724. Check NVD for updates.
Is there a patch for CVE-2026-53724?
Check the references section above for vendor advisories and patch information. Review vendor security bulletins for remediation guidance.