Vulnerability in Parse-Community Parse-Server
CVE-2026-27804
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.
Vulnerability class: POODLE (CVE-2014-3566)
EPSS: 0.002 (7.2th percentile) — read the EPSS interpretation.
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.
Affected products
- Parse-community Parse-server — versions >= 9.0.0, < 9.3.1-alpha.4, < 8.6.3
- Parseplatform Parse-server — versions 9.3.1
Weakness classification (CWE)
References
- security-advisories@github.com (x_refsource_CONFIRM, Patch, Vendor Advisory)
- security-advisories@github.com (Patch, x_refsource_MISC)
- security-advisories@github.com (Patch, x_refsource_MISC)
- security-advisories@github.com (x_refsource_MISC, Release Notes)
- security-advisories@github.com (x_refsource_MISC, Release Notes)
Frequently asked questions
- What is CVE-2026-27804?
- CVE-2026-27804 is a critical-severity vulnerability in Parse-Community Parse-Server, classified under Use of a Broken or Risky Cryptographic Algorithm. CVSS score: 9.1/10. Published 2026-02-26.
- How severe is CVE-2026-27804?
- Critical severity. CVSS v3 base score is 9.1 out of 10.