CVE-2026-27804

Parse Server: Account takeover via JWT algorithm confusion in Google auth adapter

CVSS 9.3 CRITICALEPSS 0.2%CWE-327 CWE-345

Vexday Risk Score

28Bajo

Decisión SSVC (CISA)

Track

Sin señal de explotación → monitorear

CVSS 9.3EPSS 0.2%KEV nãoPoC —Nuclei —Metasploit —Patch —

Ciclo de vida

25 feb 2026Publicada en NVD

Recomendación: Monitorear — sin señal de explotación por ahora.

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.

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N

Productos afectados

parse-community · parse-server

¿Quieres saber si tu infraestructura está expuesta a esto?

Hablar con TrueHacking →

Referencias

https://github.com/parse-community/parse-server/commit/9b94083accb7f3e72c6b8126c195c7a03dd2dfd7 https://github.com/parse-community/parse-server/commit/9d5942d50e55c822924c27b05aa98f1393e7a330 https://github.com/parse-community/parse-server/releases/tag/8.6.3 https://github.com/parse-community/parse-server/releases/tag/9.3.1-alpha.4 https://github.com/parse-community/parse-server/security/advisories/GHSA-4q3h-vp4r-prv2