SB2026063051 - Arbitrary file upload in Parse Server

Description

This security bulletin contains information about 1 vulnerability.

1) Arbitrary file upload (CVE-ID: CVE-2026-55778)

CWE-ID: CWE-434 - Unrestricted Upload of File with Dangerous Type

CVSSv4: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:A/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N/E:U/U:Clear

The vulnerability allows a remote user to perform stored cross-site scripting.

The vulnerability exists due to unrestricted upload of file with dangerous type in the file upload extension validation in Parse Server when uploading a file with a non-standard or compound extension together with a dangerous content type. A remote user can upload a specially crafted file to perform stored cross-site scripting.

Exploitation requires a storage adapter that persists and serves the uploaded content type, such as S3 or GCS, and a victim must open the uploaded file URL.

Remediation

Install update from vendor's website.

References

• https://github.com/parse-community/parse-server/security/advisories/GHSA-v8x7-r927-cc93
• https://github.com/parse-community/parse-server/pull/10505