Auth bypass in Parse-Community Parse-Server
CVE-2026-33409
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.
Vulnerability class: Broken Authentication
Published · last modified .
CVSS v3 metric
CVSS v3 base score 9.1 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N.
EPSS exploit prediction
EPSS: 0.006 (45.2th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 45th percentile — 45.2% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.005 · newest: 0.006 · change: +0.001
Affected products
- Parse-Community Parse-Server — versions < 8.6.52, >= 9.0.0, < 9.6.0-alpha.41
- Parseplatform Parse-Server — versions 9.6.0
Weakness classification (CWE)
References
- github.com/parse-community/parse-server/security/advisories/GHSA-pfj7-wv7c-22pr (Vendor Advisory)
- github.com/parse-community/parse-server/pull/10246 (Issue Tracking)
- github.com/parse-community/parse-server/pull/10247 (Issue Tracking)
- github.com/parse-community/parse-server/commit/8d7df5639c4a35768fe8b78b4580b30e… (Patch)
- github.com/parse-community/parse-server/commit/98f4ba5bcf2c199bfe6225f672e8edcd… (Patch)
Frequently asked questions
- What is CVE-2026-33409?
- CVE-2026-33409 is a critical-severity vulnerability in Parse-Community Parse-Server, classified under Improper Authentication. CVSS score: 9.1/10. Published 2026-03-24.
- How severe is CVE-2026-33409?
- Critical severity. CVSS v3 base score is 9.1 out of 10.