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CVE-2026-27804GHSA-4Q3H-VP4R-PRV2BIT-PARSE-2026-27804

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

Published
Last modified
published
Not listed in CISA KEV
Fix
Fixed in 9.3.1-alpha.4, 8.6.3
None on Exploit-DB, Metasploit or GitHub
  • Exploitation: none
  • Automatable: yes
  • Technical impact: total

Summary

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.

Timeline

  1. CVE published
  2. CISA SSVC assessment

    Exploitation: none · Automatable: yes · Technical impact: total

  3. Record last updated

Affected versions

  • parse-community parse-server

    From 9.0.0 · fixed in 9.3.1-alpha.4; fixed in 8.6.3

  • parse-servernpm

    From 9.0.0 · fixed in 9.3.1-alpha.4

  • parse-servernpm

    fixed in 8.6.3

References 5

GitHub · parse-community/parse-server