CVE-2026-55778
CVE-2026-55778 · Parse Server: Stored XSS via non-standard file extension bypassing file upload extension blocklist
This page contains facts from public vulnerability sources. Check the original advisory before updating.
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.
CVSS 2.1 · Low · EPSS 0.6% · Fix available
- Published
- Updated
Stack: node
Affected products and versions
parse-server
- Versions
- >= 9.0.0-alpha.1, < 9.9.1-alpha.11: Affected
- < 8.6.81: Affected
No fix published
parse-server npm
- Affected ranges
- SEMVER: ≥ 9.0.0, < 9.9.1-alpha.11
Update to 9.9.1-alpha.11
parse-server npm
- Affected ranges
- SEMVER: < 8.6.81
Update to 8.6.81
Original sources
- https://github.com/parse-community/parse-server/security/advisories/GHSA-v8x7-r927-cc93
- https://github.com/parse-community/parse-server/pull/10505
- https://github.com/parse-community/parse-server/pull/10506
- https://github.com/parse-community/parse-server/commit/97c6a78d19f976ec756c1295f08a8fccab90799a
- https://github.com/parse-community/parse-server/commit/be12a60d65b6e140481882037fb896b1f951df50
- https://github.com/parse-community/parse-server/releases/tag/8.6.81
- https://github.com/parse-community/parse-server/releases/tag/9.9.1-alpha.11
- https://nvd.nist.gov/vuln/detail/CVE-2026-55778