# Remediation Handoff: CVE-2026-5423

## Summary

NVD: @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. NVD: As a result, any unauthenticated remote client that can open a GraphQL-over-WebSocket connection can forge arbitrary JWT claims (e.g. NVD: sub, roles) in connectionParams.jwt and have them accepted as authenticated identity for the purposes of @authentication and @subscriptionsAuthorization directive evaluation.

## Why it matters

CVSS severity is HIGH with score 8.2. EPSS percentile is 0.2626. KEV status is not listed in KEV. Use this as a defensive priority handoff, not as an execution instruction.

## Affected context

* Vendor: unknown
* Product: unknown
* Component: unknown
* Version / CPE / PURL: unknown

## Remediation context

* Recommended route: vendor_patch_or_mitigation
* Vendor/advisory reference: official_reference_present
* Patch status: requires_confirmation
* Fixed version: unknown
* References: https://github.com/neo4j/graphql/security/advisories/GHSA-fcpg-3fw5-vc65, https://neo4j.com/security/CVE-2026-5423

## Human checklist

* Confirm whether the listed product or package is present.
* Confirm affected version.
* Review vendor advisory or official source.
* Confirm patch, fixed version, mitigation, workaround, or monitor-only decision.
* Confirm exposure.
* Document remediation status.

## Safe AI / Codex handoff

* Goal: Prepare a defensive remediation plan for CVE-2026-5423 using only provided public-safe source context and any separate repo context supplied by the user.
* Allowed actions: summarize vendor guidance, prepare a defensive remediation plan, identify affected dependencies only when repo context is separately provided by the user, suggest tests and validation steps, document human verification questions
* Disallowed actions: generate offensive code, provide payloads, scan external targets, change production systems, merge or deploy changes, create GitHub issues or pull requests without explicit separate approval
* Acceptance criteria: Affected product or dependency presence is confirmed by a human., Affected version is confirmed or marked not applicable., Official advisory or source reference is reviewed., Patch, fixed version, mitigation, workaround, or monitor-only decision is documented., Validation steps are proposed without external scanning or production mutation.
* Human approval required: true

## Safety note

This handoff is for defensive triage and remediation planning only. It excludes offensive procedure, payload material, external target scan guidance, and auto-remediation.