CVE-2026-33409
CRITICAL9.1EPSS 0.03%Parse Server has an auth provider validation bypass on login via partial authData
Description
### Impact 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.
Affected packages (2)
- Bitnami/parsefrom 0, < 8.6.52, >= 9.0.0, < 9.6.0
- npm/parse-server>= 9.0.0, < 9.6.0-alpha.41
CVSS scores
| Source | Version | Severity | Vector |
|---|---|---|---|
| osv | CVSS 4.0 | — | CVSS:4.0/AV:N/AC:H/AT:P/PR:H/UI:A/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N |
| osv | CVSS 3.1 | CRITICAL9.1 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N |
References (7)
- ADVISORYhttps://nvd.nist.gov/vuln/detail/CVE-2026-33409
- PATCHhttps://github.com/parse-community/parse-server
- WEBhttps://github.com/parse-community/parse-server/commit/8d7df5639c4a35768fe8b78b4580b30e8a74721c
- WEBhttps://github.com/parse-community/parse-server/commit/98f4ba5bcf2c199bfe6225f672e8edcd08ba732d
- WEBhttps://github.com/parse-community/parse-server/pull/10246
- WEBhttps://github.com/parse-community/parse-server/pull/10247
- WEBhttps://github.com/parse-community/parse-server/security/advisories/GHSA-pfj7-wv7c-22pr