CVE-2026-33409: Parse Server has an auth provider validation bypass on login via partial authData
(updated )
An authentication bypass vulnerability allows an attacker to log in as any user who has linked a third-party authentication provider, without knowing the user’s credentials. The attacker only needs to know the user’s provider ID to gain full access to their account, including a valid session token.
This affects Parse Server deployments where the server option allowExpiredAuthDataToken is set to true. The default value is false.
References
- github.com/advisories/GHSA-pfj7-wv7c-22pr
- github.com/parse-community/parse-server
- github.com/parse-community/parse-server/commit/8d7df5639c4a35768fe8b78b4580b30e8a74721c
- github.com/parse-community/parse-server/commit/98f4ba5bcf2c199bfe6225f672e8edcd08ba732d
- github.com/parse-community/parse-server/pull/10246
- github.com/parse-community/parse-server/pull/10247
- github.com/parse-community/parse-server/security/advisories/GHSA-pfj7-wv7c-22pr
- nvd.nist.gov/vuln/detail/CVE-2026-33409
Code Behaviors & Features
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