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.
https://github.com/parse-community/parse-server/security/advisories/GHSA-v8x7-r927-cc93
https://github.com/parse-community/parse-server/releases/tag/9.9.1-alpha.11
https://github.com/parse-community/parse-server/releases/tag/8.6.81
https://github.com/parse-community/parse-server/pull/10506
https://github.com/parse-community/parse-server/pull/10505
https://github.com/parse-community/parse-server/commit/be12a60d65b6e140481882037fb896b1f951df50
https://github.com/parse-community/parse-server/commit/97c6a78d19f976ec756c1295f08a8fccab90799a
Published: 2026-07-08
Updated: 2026-07-10
Base Score: 4.3
Vector: CVSS2#AV:N/AC:M/Au:N/C:N/I:P/A:N
Severity: Medium
Base Score: 6.1
Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
Severity: Medium
Base 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
Severity: Low
EPSS: 0.00406