Arbitrary file upload in Parse-Community Parse-Server
CVE-2026-55778
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.
Vulnerability class: Unrestricted File Upload
Published · last modified .
EPSS exploit prediction
EPSS: 0.006 (44.5th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 44th percentile — 44.5% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.006 · newest: 0.006 · change: 0.000
Affected products
- Parse-Community Parse-Server — versions >= 9.0.0-alpha.1, < 9.9.1-alpha.11, < 8.6.81
Weakness classification (CWE)
References
- github.com/parse-community/parse-server/commit/97c6a78d19f976ec756c1295f08a8fcc…
- github.com/parse-community/parse-server/commit/be12a60d65b6e140481882037fb896b1…
- github.com/parse-community/parse-server/pull/10505
- github.com/parse-community/parse-server/pull/10506
- github.com/parse-community/parse-server/releases/tag/8.6.81
- github.com/parse-community/parse-server/releases/tag/9.9.1-alpha.11
- github.com/parse-community/parse-server/security/advisories/GHSA-v8x7-r927-cc93