CVE-2026-27804
Parse Server: Account takeover via JWT algorithm confusion in Google auth adapter
At a glance
- Source
- NVD
- EPSS
- EPSS 0.20 % · percentile 10 ()
- State
- PUBLISHED
- Published
- Updated
- Assigner
- GitHub_M
- NVD status
- Analyzed
Description
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.
Weaknesses (CWE)
- CWE-327 — Use of a Broken or Risky Cryptographic Algorithm
- CWE-345 — Insufficient Verification of Data Authenticity
References
- https://github.com/parse-community/parse-server/security/advisories/GHSA-4q3h-vp4r-prv2
- 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
Scores
| Version | Score | Vector | Scored by |
|---|---|---|---|
| CVSS 4.0 | CRITICAL 9.3 | 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 | GitHub_M |
| CVSS 4.0 | CRITICAL 9.3 | 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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X | NVD · security-advisories@github.com (Secondary) |
| CVSS 3.1 | CRITICAL 9.1 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N | NVD · nvd@nist.gov (Primary) |
Advisories
- GHSA-4q3h-vp4r-prv2 — Parse Server: Account takeover via JWT algorithm confusion in Google auth adapter
European references
- ENISA EUVD · EUVD-2026-8774
- GCVE · GCVE-0-2026-27804
Affected configurations (NVD CPE)
cpe:2.3:a:parseplatform:parse-server:*:*:*:*:*:node.js:*:*< 8.6.3cpe:2.3:a:parseplatform:parse-server:*:*:*:*:*:node.js:*:*≥ 9.0.0 < 9.3.1cpe:2.3:a:parseplatform:parse-server:9.3.1:alpha1:*:*:*:node.js:*:*cpe:2.3:a:parseplatform:parse-server:9.3.1:alpha2:*:*:*:node.js:*:*cpe:2.3:a:parseplatform:parse-server:9.3.1:alpha3:*:*:*:node.js:*:*
Affected products
| Product | Versions |
|---|---|
| parse-community · parse-server | affected >= 9.0.0, < 9.3.1-alpha.4 ; affected < 8.6.3 |
Sources
| Source | Licence |
|---|---|
| CVE List (CVEProject cvelistV5) | CVE Program Terms of Use |
| EPSS (FIRST.org) | FIRST — attribution requested |
| ENISA EUVD | ENISA — reproduction authorised, source acknowledged |
| NVD (NIST) via fkie-cad/nvd-json-data-feeds | Public domain — this product uses data from the NVD API but is not endorsed or certified by the NVD |