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.

Project Subscriptions

Vendors Products
Parse Community Subscribe
Parse Server Subscribe
Advisories

No advisories yet.

Fixes

Solution

No solution given by the vendor.


Workaround

No workaround given by the vendor.

History

Fri, 12 Jun 2026 20:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


Fri, 12 Jun 2026 20:00:00 +0000

Type Values Removed Values Added
First Time appeared Parse Community
Parse Community parse Server
Vendors & Products Parse Community
Parse Community parse Server

Fri, 12 Jun 2026 18:45:00 +0000

Type Values Removed Values Added
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.
Title Parse Server: Stored XSS via trailing-dot filename bypassing file upload extension blocklist
Weaknesses CWE-434
CWE-79
References
Metrics cvssV4_0

{'score': 2.1, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:P/VC:N/VI:L/VA:N/SC:L/SI:L/SA:N'}


Projects

Sign in to view the affected projects.

cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published:

Updated: 2026-06-12T20:01:13.569Z

Reserved: 2026-06-10T16:43:31.242Z

Link: CVE-2026-53724

cve-icon Vulnrichment

Updated: 2026-06-12T20:01:09.023Z

cve-icon NVD

Status : Received

Published: 2026-06-12T19:16:30.220

Modified: 2026-06-12T19:16:30.220

Link: CVE-2026-53724

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-06-12T19:45:27Z

Weaknesses