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.
- CVSS 4.0
- 2.1
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 - EPSS
- 0.6% chance of exploitation in the next 30 days; higher than 45% of CVEs (scores of 2026-10-25)
- CWE
- CWE-434
- Published
- Modified
- Record from
- the NVD, synced
Packages (OSV)
| Advisory | Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|---|
| GHSA-v8x7-r927-cc93 | npm | parse-server | >=9.0.0 <9.9.1-alpha.11 | 9.9.1-alpha.11 |
| GHSA-v8x7-r927-cc93 | npm | parse-server | <8.6.81 | 8.6.81 |
References
- 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/pull/10505
- https://github.com/parse-community/parse-server/pull/10506
- https://github.com/parse-community/parse-server/releases/tag/8.6.81