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.
Metrics
Affected Vendors & Products
Advisories
| Source | ID | Title |
|---|---|---|
Github GHSA |
GHSA-4q3h-vp4r-prv2 | Parse Server: Account takeover via JWT algorithm confusion in Google auth adapter |
Fixes
Solution
No solution given by the vendor.
Workaround
No workaround given by the vendor.
References
History
Thu, 26 Feb 2026 00:00:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| 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. | |
| Title | Parse Server: Account takeover via JWT algorithm confusion in Google auth adapter | |
| Weaknesses | CWE-327 CWE-345 |
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| References |
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| Metrics |
cvssV4_0
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Projects
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Status: PUBLISHED
Assigner: GitHub_M
Published:
Updated: 2026-02-25T23:48:20.858Z
Reserved: 2026-02-24T02:31:33.266Z
Link: CVE-2026-27804
No data.
Status : Received
Published: 2026-02-26T00:16:25.793
Modified: 2026-02-26T00:16:25.793
Link: CVE-2026-27804
No data.
OpenCVE Enrichment
No data.
Github GHSA