Parse Server is an open source backend that can be deployed to any infrastructure that can run Node.js. Prior to versions 8.6.52 and 9.6.0-alpha.41, 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. This issue has been patched in versions 8.6.52 and 9.6.0-alpha.41.
PUBLISHED5.2CWE-287
Parse Server: Auth provider validation bypass on login via partial authData
Problem type
Affected products
parse-community
parse-server
< 8.6.52 - AFFECTED
>= 9.0.0, < 9.6.0-alpha.41 - AFFECTED
References
https://github.com/parse-community/parse-server/security/advisories/GHSA-pfj7-wv7c-22pr
https://github.com/parse-community/parse-server/security/advisories/GHSA-pfj7-wv7c-22pr
https://github.com/parse-community/parse-server/pull/10246
https://github.com/parse-community/parse-server/pull/10246
https://github.com/parse-community/parse-server/pull/10247
https://github.com/parse-community/parse-server/pull/10247
https://github.com/parse-community/parse-server/commit/8d7df5639c4a35768fe8b78b4580b30e8a74721c
https://github.com/parse-community/parse-server/commit/8d7df5639c4a35768fe8b78b4580b30e8a74721c
https://github.com/parse-community/parse-server/commit/98f4ba5bcf2c199bfe6225f672e8edcd08ba732d
https://github.com/parse-community/parse-server/commit/98f4ba5bcf2c199bfe6225f672e8edcd08ba732d
GitHub Security Advisories
GHSA-pfj7-wv7c-22pr
Parse Server has an auth provider validation bypass on login via partial authData
https://github.com/advisories/GHSA-pfj7-wv7c-22prImpact
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.
Patches
Auth providers are now always validated on login, regardless of the allowExpiredAuthDataToken setting. The option allowExpiredAuthDataToken has been deprecated and will be removed in a future major version.
Workarounds
Set allowExpiredAuthDataToken to false (the default) or remove the option from the server configuration.
JSON source
https://cveawg.mitre.org/api/cve/CVE-2026-33409Click to expand
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"dateUpdated": "2026-03-24T18:11:36.824Z",
"dateReserved": "2026-03-19T17:02:34.171Z",
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