CVE-2026-27804
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.
How to fix
- parseplatform parse-server8.6.3, 9.3.1 or later
- parse-server9.3.1-alpha.4, 8.6.3 or later
Affected products
| Product | Affected versions | Fixed in |
|---|---|---|
| parseplatform parse-server | v < 8.6.3, 9.0.0 ≤ v < 9.3.1, 9.3.1 | 8.6.3, 9.3.1 |
| parse-servernpm | 9.0.0 ≤ v < 9.3.1-alpha.4, v < 8.6.3 | 9.3.1-alpha.4, 8.6.3 |
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Attack Surface Management
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