CVE-2026-27804
February 25, 2026
Parse Server is an open source backend that can be deployed to any infrastructure that can run Node.js. Prior to versions 8.6.3 and 9.1.1-alpha.4, an unauthenticated attacker can forge a Google authentication token with "alg: "none"" to log in as any user linked to a Google account, without knowing their credentials. All deployments with Google authentication enabled are affected. The fix in versions 8.6.3 and 9.1.1-alpha.4 hardcodes the expected "RS256" algorithm instead of trusting the JWT header, and replaces the Google adapter's custom key fetcher with "jwks-rsa" which rejects unknown key IDs. As a workaround, dsable Google authentication until upgrading is possible.
Affected Packages
https://github.com/parse-community/parse-server.git (GITHUB):
Affected version(s) >=9.0.0-alpha.1 <9.3.1-alpha.4Fix Suggestion:
Update to version 9.3.1-alpha.4https://github.com/parse-community/parse-server.git (GITHUB):
Affected version(s) >=2.0.0 <8.6.3Fix Suggestion:
Update to version 8.6.3parse-server (NPM):
Affected version(s) >=1.0.0 <8.6.3Fix Suggestion:
Update to version 8.6.3parse-server (NPM):
Affected version(s) >=9.0.0 <9.3.1-alpha.4Fix Suggestion:
Update to version 9.3.1-alpha.4Related Resources (7)
Do you need more information?
Contact UsCVSS v4
Base Score:
9.3
Attack Vector
NETWORK
Attack Complexity
LOW
Attack Requirements
NONE
Privileges Required
NONE
User Interaction
NONE
Vulnerable System Confidentiality
HIGH
Vulnerable System Integrity
HIGH
Vulnerable System Availability
NONE
Subsequent System Confidentiality
NONE
Subsequent System Integrity
NONE
Subsequent System Availability
NONE
CVSS v3
Base Score:
9.1
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
HIGH
Integrity
HIGH
Availability
NONE
Weakness Type (CWE)
EPSS
Base Score:
0.03
