Vulnerability · Published Aug 6, 2026 · Assigned by Neo4j
CVE-2026-5423Subscription Authentication Bypass via Unverified connectionParams.jwt
High 8.2
In plain English
A high-severity security flaw in graphql from neo4j. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.6% (higher than 48% of all known vulnerabilities).
Official description
@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.
Affected products (as reported)
Weakness: CWE-302 · Vector: 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
References
- https://neo4j.com/security/CVE-2026-5423 vendor-advisory
- https://github.com/neo4j/graphql/security/advisories/GHSA-fcpg-3fw5-vc65 third-party-advisory