GHSA-4q3h-vp4r-prv2
Parse Server: Account takeover via JWT algorithm confusion in Google auth adapter
At a glance
- Published
- Updated
- CVE
- CVE-2026-27804
- Aliases
- BIT-parse-2026-27804
- CVSS_V4
- 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
Description
### Impact 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. ### Patches The fix 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. ### Workarounds Disable Google authentication until you can upgrade. ### References - GitHub advisory: https://github.com/parse-community/parse-server/security/advisories/GHSA-4q3h-vp4r-prv2 - Fixed in Parse Server 9.3.1-alpha.4: https://github.com/parse-community/parse-server/releases/tag/9.3.1-alpha.4 - Fixed in Parse Server 8.6.3: https://github.com/parse-community/parse-server/releases/tag/8.6.3
Affected packages
| Package | Versions |
|---|---|
| npm · parse-server | introduced 9.0.0, fixed 9.3.1-alpha.4 |
| npm · parse-server | introduced 0, fixed 8.6.3 |
References
- https://github.com/parse-community/parse-server/security/advisories/GHSA-4q3h-vp4r-prv2 WEB
- https://nvd.nist.gov/vuln/detail/CVE-2026-27804 ADVISORY
- https://github.com/parse-community/parse-server/commit/9b94083accb7f3e72c6b8126c195c7a03dd2dfd7 WEB
- https://github.com/parse-community/parse-server/commit/9d5942d50e55c822924c27b05aa98f1393e7a330 WEB
- https://github.com/parse-community/parse-server PACKAGE
- https://github.com/parse-community/parse-server/releases/tag/8.6.3 WEB
- https://github.com/parse-community/parse-server/releases/tag/9.3.1-alpha.4 WEB
Sources
| Source | Licence |
|---|---|
| OSV.dev | CC-BY 4.0 — GitHub Advisory Database |