---
cve: "CVE-2026-5423"
severity: "HIGH"
cvss: 8.2
epss: "0.4%"
vendor: "neo4j"
kev: false
exploited: false
published: "2026-08-06 15:15:29"
tags: [cve, security, high]
source: tsecurity.de CVE-Dossier
exported: "2026-09-28T21:36:30+02:00"
---

# CVE-2026-5423

> 8.2 HIGH · 🧪 PoC

## Beschreibung

@neo4j/graphql library versions prior to 7.5.6 fail to verify the authenticity of a client-supplied, pre-decoded JWT object passed through GraphQL subscription connectionParams. As a result, any unauthenticated remote client that can open a GraphQL-over-WebSocket connection can forge arbitrary JWT claims (e.g. sub, roles) in connectionParams.jwt and have them accepted as authenticated identity for the purposes of @authentication and @subscriptionsAuthorization directive evaluation. This allows a fully unauthenticated attacker to receive subscription events that should be restricted to specific authenticated roles/users.
Upgrade the library to versions 7.5.6+ or 5.12.14+. v6 is end-of-life and will not receive a fix.

## CISA-Anreicherung (vulnrichment/ADP)

- CISA-SSVC (Coordinator, v2.0.3):
  - Exploitation: **none**
  - Automatable: **no**
  - Technical Impact: **partial**

## CVSS-Vektor

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

| Metrik | Wert | Bewertung |
|---|---|---|
| AV Angriffsvektor | Netzwerk | bad |
| AC Komplexität | Gering | bad |
| PR Privilegien | Keine | bad |
| UI Interaktion | Keine | bad |

## Patch verfügbar (OSV)

- 57c53493949e67f3bf72c2b29370632d61aae95e (Commit)
- 42c91ebed8d28b9391076979ea8ce3875b83cb82 (Commit)

## Referenzen

- <https://neo4j.com/security/CVE-2026-5423>
- <https://github.com/neo4j/graphql/security/advisories/GHSA-fcpg-3fw5-vc65>

---
_Exportiert aus dem [tsecurity.de CVE-Dossier](https://tsecurity.de/cve?cve=CVE-2026-5423) · Datenquellen: EUVD (ENISA), NVD, OSV, CISA KEV, FIRST EPSS, Exploit-DB, BSI WID (CSAF)_