Parse Server is an open source backend that can be deployed to any infrastructure that can run Node.js. Prior to versions 8.6.58 and 9.6.0-alpha.52, an unauthenticated attacker can cause denial of service by sending authentication requests with arbitrary, unconfigured provider names. The server executes a database query for each unconfigured provider before rejecting the request, and since no database index exists for unconfigured providers, each request triggers a full collection scan on the user database. This can be parallelized to saturate database resources. This issue has been patched in versions 8.6.58 and 9.6.0-alpha.52.
https://github.com/parse-community/parse-server/security/advisories/GHSA-g4cf-xj29-wqqr
https://github.com/parse-community/parse-server/pull/10271
https://github.com/parse-community/parse-server/pull/10270
https://github.com/parse-community/parse-server/commit/fbac847499e57f243315c5fc7135be1d58bb8e54
https://github.com/parse-community/parse-server/commit/40eb442e02672986730007d0a1edb22c1c4bd357
Published: 2026-03-24
Updated: 2026-03-25
Base Score: 7.8
Vector: CVSS2#AV:N/AC:L/Au:N/C:N/I:N/A:C
Severity: High
Base Score: 7.5
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Severity: High
Base Score: 8.7
Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
Severity: High
EPSS: 0.00122