CVE-2026-27804
Severity CVSS v4.0:
CRITICAL
Type:
CWE-327
Use of a Broken or Risky Cryptographic Algorithm
Publication date:
26/02/2026
Last modified:
04/03/2026
Description
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.
Impact
Base Score 4.0
9.30
Severity 4.0
CRITICAL
Base Score 3.x
9.10
Severity 3.x
CRITICAL
Vulnerable products and versions
| CPE | From | Up to |
|---|---|---|
| cpe:2.3:a:parseplatform:parse-server:*:*:*:*:*:node.js:*:* | 8.6.3 (excluding) | |
| cpe:2.3:a:parseplatform:parse-server:*:*:*:*:*:node.js:*:* | 9.0.0 (including) | 9.3.1 (excluding) |
| cpe:2.3:a:parseplatform:parse-server:9.3.1:alpha1:*:*:*:node.js:*:* | ||
| cpe:2.3:a:parseplatform:parse-server:9.3.1:alpha2:*:*:*:node.js:*:* | ||
| cpe:2.3:a:parseplatform:parse-server:9.3.1:alpha3:*:*:*:node.js:*:* |
To consult the complete list of CPE names with products and versions, see this page
References to Advisories, Solutions, and Tools
- https://github.com/parse-community/parse-server/commit/9b94083accb7f3e72c6b8126c195c7a03dd2dfd7
- https://github.com/parse-community/parse-server/commit/9d5942d50e55c822924c27b05aa98f1393e7a330
- https://github.com/parse-community/parse-server/releases/tag/8.6.3
- https://github.com/parse-community/parse-server/releases/tag/9.3.1-alpha.4
- https://github.com/parse-community/parse-server/security/advisories/GHSA-4q3h-vp4r-prv2